SLUS550E DECEMBER 2002 REVISED JUNE 2005 v1.1 COMPLIANT GAUGE WIT
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bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
v1.1 COMPLIANT GAUGE WITH bq29312
FEATURES
Provides Accurate Measurement Available Charge Li-Ion Li-Polymer Batteries Supports Smart Battery Specification (SBS) V1.1 Integrated Time Base Removes Need External Crystal with Optional Crystal input Works With bq29312 Analog Front (AFE) Protection Provide Complete Pack Electronics 7.2-V, 10.8-V 14.4-V Battery Packs With External Components Based Powerful Low-Power RISC Core With High-Performance Peripherals Integrated FLASH Memory Eliminates Need External Configuration EEPROM Uses 16-Bit Delta Sigma Converter Accurate Voltage Temperature Measurements Measures Charge Flow Using High Resolution 16-Bit Integrating Converter Better Than 0.65-nVh Resolution Self-Calibrating Offset Error Less Than 1-µV Programmable Cell Modeling Maximum Battery Fuel Gauge Accuracy Drives 5-Segment Display Remaining Capacity Indication 38-Pin TSSOP (DBT)
DESCRIPTION
bq2084 SBS-compliant gauge battery pack in-system installation maintains accurate record available charge Li-ion Li-polymer batteries. bq2084 monitors capacity other critical parameters battery pack reports information system host controller over serial communication bus. designed work with bq29312 analog front-end (AFE) protection maximize functionality safety minimize component count cost smart battery circuits. Using information from bq2084, host controller manage remaining battery power extend system time much possible. bq2084 uses integrating converter with continuous sampling measurement battery charge discharge currents. Optimized coulomb counting portable applications, self-calibrating integrating converter resolution better than 0.65-nVh offset measurement error less than 1-µV (typical). voltage temperature reporting, bq2084 uses 16-bit A-to-D converter. conjunction with bq29312, onboard also monitors pack individual cell voltages battery pack allows bq2084 generate control signals necessary implement cell balancing required safety protection Li-ion Li-polymer battery chemistries. bq2084 supports Smart Battery Data (SBData) commands charge-control functions. communicates data using System Management (SMBus) 2-wire protocol. data available include battery's remaining capacity, temperature, voltage, current remaining run-time predictions. bq2084 provides drivers push-button input depict remaining battery capacity from full empty 20%, 25%, increments with 5-segment display.
APPLICATIONS
Notebook Medical Test Equipment Portable Instrumentation
Please aware that important notice concerning availability, standard warranty, critical applications Texas Instruments semiconductor products disclaimers thereto appears this data sheet.
PRODUCTION DATA information current publication date. Products conform specifications terms Texas Instruments standard warranty. Production processing does necessarily include testing parameters.
Copyright 2002-2005, Texas Instruments Incorporated
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
These devices have limited built-in protection. leads should shorted together device placed conductive foam during storage handling prevent electrostatic damage gates.
DESCRIPTION (CONTINUED)
bq2084 contains bytes internal data flash memory, which store configuration information. information includes nominal capacity voltage, self-discharge rate, rate compensation factors, other programmable cell-modeling factors used accurately adjust remaining capacity use-conditions based time, rate, temperature. bq2084 also automatically calibrates learns true battery capacity course discharge cycle from programmable near full near empty levels. bq29312 analog front-end (AFE) protection used maximize functionality safety minimize component count cost smart battery circuits. bq29312 protection provides power bq2084 from series Li-ion cell stack, eliminating need external regulator circuit. ORDERING INFORMATION
-20°C 85°C PACKAGE 38-PIN TSSOP (DBT) bq2084DBT
bq2084 available taped reeled. suffix device type (e.g., bq2084DBTR) order tape reel version.
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted
UNIT Supply voltage range, relative
-0.3 -0.3 -0.3 -20°C 85°C -65°C 150°C
Open-drain pins, V(IOD) relative Input voltage range other pins, relative Tstg Operating free-air temperature range Storage temperature range
Stresses beyond those listed under "absolute maximum ratings" cause permanent damage device. These stress ratings only, functional operation device these other conditions beyond those indicated under "recommended operating conditions" implied. Exposure absolute-maximum-rated conditions extended periods affect device reliability. refers common node V(SSA), V(SSD), V(SSP).
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ELECTRICAL CHARACTERISTICS
-20°C 85°C unless otherwise noted
PARAMETER I(SLP) Supply voltage Operating mode current Low-power storage mode current TEST CONDITIONS VDDA VDDD flash programming LEDs active Sleep mode -0.3 -0.3 0.25 -0.25 ±0.25 V-1.0
POWER RESET BEHAVIOR FREE-AIR TEMPERATURE
2.50 2.45 2.40 2.35 2.30 2.25 2.20 2.15 2.10 Vhys VIT140 Free-Air Temperature Hysterisis Voltage
UNIT
Output voltage SMBC, SMBD, SDATA, SCLK, SAFE, LED1-LED5 Input voltage SMBC, SMBD, SDATA, SCLK, EVENT, PRES, PFIN DISP Input voltage high SMBC, SMBD, SDATA, SCLK, EVENT, PRES, PFIN DISP Input voltage range VIN, Input voltage range SR1, Input impedance SR1, Input impedance VIN, Negative-going voltage input Power-on reset hysteresis
0.25
V(AI1) V(AI2) Z(AI1) Z(AI2) VIT+ Vhys
POWER-ON RESET
INTEGRATING CHARACTERISTICS
-20°C 85°C unless otherwise noted
PARAMETER V(SR) V(SROS) Input voltage range, V(SR2) V(SR1) Input offset Integral nonlinearity error FAST -0.1 Vref TEST CONDITIONS V(SR2)- V(SR1) -0.25 0.004% 0.018% 0.25 UNIT
SWITCHING CHARACTERISTICS
-20°C 85°C unless otherwise noted
PARAMETER t(SP) Start-up time
Negative Going Input Threshold Voltage
TEST CONDITIONS ±0.5% frequency error
UNIT
frequency error measured from trimmed frequency internal system clock, which oscillator frequency, nominally 4.194 MHz.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
OSCILLATOR
-20°C 85°C (unless otherwise noted) (TYP: 25°C)
PARAMETER f(eio) f(dio) f(sio) f(sxo) Frequency error from 32.768 Frequency drift
TEST CONDITIONS ROSC 100k XCK1 XTAL ROSC 100k, 50°C ROSC 100k XCK1 XTAL
-0.25
0.25
UNIT
Start-up time
frequency drift measured from trimmed frequency 25°C. start-up time defined time takes oscillator output frequency
DATA FLASH MEMORY CHARACTERISTICS
-20°C 85°C unless otherwise noted
PARAMETER t(WORDPROG) I(DDPROG) Data retention Flash programming write-cycles Word programming time Flash-write supply current TEST CONDITIONS UNIT Years Cycles
Assured design. production tested.
REGISTER BACKUP
PARAMETER I(RBI) V(RBI) data-retention input current data-retention voltage
TEST CONDITIONS VRBI
UNIT
Specified design. production tested.
SMBus TIMING SPECIFICATIONS
-20°C 85°C unless otherwise noted
PARAMETER f(SMB) f(MAS) t(BUF) T(HD:STA) t(SU:STA) t(SU:STO) t(HD:DAT) tSU:DAT) t(TIMEOUT) t(LOW) t(HIGH) tLOW:SEXT) tLOW:MEXT SMBus operating frequency SMBus master clock frequency free time between start stop Hold time after (repeated) start Repeated start setup time Stop setup time Data hold time Data setup time Error signal/detect Clock period Clock high period Cumulative clock slave extend time Cumulative clock master extend time Clock/data fall time Clock/data rise time
TEST CONDITIONS Slave mode, SMBC duty cycle Master mode, clock slave extend
51.2
UNIT
Receive mode Transmit mode
1000
(VILMAX 0.15 (VIHMIN 0.15 (VILMAX- 0.15
bq2084 times when clock exceeds t(TIMEOUT) t(HIGH) Max. minimum idle time. SMBC causes reset transaction involving bq2084 that progress. t(LOW:SEXT) cumulative time slave device allowed extend clock cycles message from initial start stop. t(LOW:MEXT) cumulative time master device allowed extend clock cycles message from initial start stop.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
SMBus TIMING DIAGRAMS
SYSTEM DIAGRAM
Discharge Charge Pre-Charge FETs
Fuse Pack bq2084 Pre-Charge Control Fail-Safe Protection Input bq29312 Drive Pre-Charge Drive
Pres
Power Management LDO, TOUT Power Mode Control Temperature Measurement TINT Error Bytes User Flash Clock Generator
Cell Balancing Drive Level Overvoltage Protection
LDO, Therm Output Drive UVLO System Watchdog
Delay Counters
Cell Balancing Algorithm Control SMBus v1.1 Data System Interface System Interface Registers
bq29312 RAM/Comms Validation Level Protection Pack Under Voltage Power Mode Control Level Protection Cell Pack Voltage Measurement
Power Mode Control
2-Tier Overcurrent Protection Voltage Level Translator
Capacity Prediction Error
Pack Sense Resistor
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ASSIGNMENTS
TSSOP (DBT) (TOP VIEW)
VSSA PRES SCLK VDDD SDATA VSSD SAFE SMBC SMBD DISP PFIN VSSD
VSSD CLKOUT XCK1/VSSA XCK2/ROSC FILT VDDA VSSA VSSA MRST EVENT LED1 LED2 LED3 LED4 LED5
Terminal Functions
TERMINAL NAME CLKOUT DISP FILT EVENT LED1 LED2 LED3 LED4 LED5 MRST PFIN PRES SAFE SCLK SDATA SMBC SMBD Master reset input that forces device into reset when held high connection Active input detect secondary protector output status Active input sense system insertion Output pull /PRES detection Register backup that provides backup potential bq2084 data registers during periods operating voltage. accepts storage capacitor battery input. Active output additional level safety protection, such intentionally blowing fuse Communication clock bq29312 Data transfer from bq29312 SMBus clock open-drain bidirectional used clock data transfer from bq2084 SMBus data open-drain bidirectional used transfer address data from bq2084 Connections small-value sense resistor monitor battery charge- discharge-current display segments that each drive external 32.768-kHz output bq29312 Display control drivers LED1 through LED5 Analog input connected external filter Input from bq29312 XALERT output DESCRIPTION
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ASSIGNMENTS (continued)
Terminal Functions (continued)
TERMINAL NAME VDDA VDDD VSSA VSSD XCK1/VSSA XCK2/ROSC DESCRIPTION Thermistor connection monitor temperature Positive supply analog circuitry Positive supply digital circuitry pins Single cell voltage input from bq29312 Negative supply analog circuitry Negative supply digital circuitry 32.768-kHz crystal oscillator input connected VSSA internal oscillator used. 32.768-kHz crystal oscillator output connected 100-kW, better resistor internal oscillator used.
FUNCTIONAL DESCRIPTION Oscillator Function
bq2084 internal external oscillator. powerup, bq2084 automatically attempts start internal oscillator. 100-k resistor connected ROSC (pin 33), then attempts start external 32.768-kHz crystal oscillator. Install either 100-k ROSC resistor 32.768-kHz crystal, both. performance internal oscillator depends tolerance 100-k resistor connected between RSOC (pin VSSA (pin 34). recommended that this resistor close bq2084 possible, that specification ±0.1% tolerance temperature drift better. 12-pF crystal used, place close XCK1 (pin XCK2 (pin pins possible. layout around these pins components degrade oscillator performance carefully implemented. average oscillator temperature-drift error during learning charge discharge cycle introduces equal capacity-prediction error learned full-charge capacity value(FCC).
System Present Operation
When bq2084 detects that battery inserted into system state PRES input, bq2084 enters normal operating mode sets PRES PackStatus(). When pack removed from system PRES input high, then bq2084 enters battery removed state turns charge discharge FETs, enables 0-V/precharging FET.
General Operation
bq2084 determines battery capacity monitoring current input removed from rechargeable battery. addition measuring charge discharge, bq2084 measures individual cell voltages, pack voltage, temperature, current, estimates battery self-discharge, monitors battery low-voltage thresholds using features bq29312 device. bq2084 measures charge discharge activity monitoring voltage across small-value series sense resistor between cell-stack negative terminal negative terminal battery pack. available battery charge determined monitoring this voltage correcting measurement environmental operating conditions. bq2084 interfaces with bq29312 perform battery protection, cell balancing voltage translation functions. bq2084 accept thermistor (default Semitec 103AT) temperature measurement also configured internal temperature sensor. bq2084 uses temperature monitor battery pack compensate self-discharge estimate.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
FUNCTIONAL DESCRIPTION (continued) Measurements
bq2084 uses integrating sigma-delta analog-to-digital converter (ADC) current measurement second sigma-delta individual cell battery voltage temperature measurement. individual cell pack voltages, Voltage(), Current(), AverageCurrent() Temperature updated one-second intervals during normal operation. Charge Discharge Counting integrating measures charge discharge flow battery monitoring small-value sense resistor between pins. integrating measures bipolar signals from -0.25 0.25 bq2084 detects charge activity when V(SR1)- V(SR2) positive discharge activity when V(SR1)- V(SR2) negative. bq2084 continuously integrates signal over time, using internal counter. fundamental rate counter 0.65 nVh. bq2084 updates RemainingCapacity() with charge discharge accumulated this internal counter once every second. Offset Calibration bq2084 provides auto-calibration feature cancel voltage offset error across maximum charge measurement accuracy. When SMBus lines stay minimum seconds, bq2084 automatically calibrates internally connecting measuring internal offset. bq2084 capable automatic offset calibration below Digital Filter bq2084 does measure charge discharge activity that falls below digital filter threshold value. digital filter threshold programmed Digital Filter 0x2C), should sufficiently high prevent false signal detection with current flowing through sense resistor. Voltage While monitoring charge discharge currents, bq2084 monitors individual series cell voltages through bq29312. bq2084 configures bq29312 connect selected cell CELL bq29312, which typically connected bq2084. internal bq2084 then measures voltage scales appropriately. bq2084 then reports Voltage() individual cell voltages VCELL1(), VCELL2(), VCELL3(), VCELL4(). Also, SMBus command (0x45) returns measured Reading PACK input AFE. Current bq2084 uses inputs measure calculate battery charge discharge current. This value reported command Current(). AverageCurrent(), implemented single-pole filter with 14.5-s time constant. Temperature input bq2084 conjunction with thermistor measures battery temperature shown Figure bq2084 reports temperature command Temperature(). bq2084 also configured internal temperature sensor setting Misc Configuration 0x2a-0x2b). Data flash locations 0xb5-0xc0 must also changed prescribed values internal temperature sensor selected.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
FUNCTIONAL DESCRIPTION (continued)
Table Data Flash Settings Internal External Temperature Sensor
LABEL Misc. Config Const1 Const2 Const3 Const4 Temp Temp LOCATION (Hex) (0x2a) 164/5 (0xb5/6) 166/7 (0xb7/8) 168/9 (0xb9/a) 170/1 (0xbb/c) 172/3 (0xbd/e) 174/5 (0xbf/c0) INTERNAL TEMP SENSOR SETTING (Hex) (0x0000) (0x0000) -11136 (0xd480) 5734 (0x1666) (0x0000) 5734 (0x1666) EXTERNAL TEMP SENSOR SETTING (Semitec 103AT) (Hex) -28285 (0x9183) 20848 (0x5170) -7537 (0xe28f) 4012 (0x0fac) (0x000) 4012 (0x0fac)
Gauge Operation
General operational overview Figure illustrates gauge operation bq2084. Table describes bq2084 registers.
Figure bq2084 Gauging Operational Overview bq2084 accumulates measure charge discharge currents, estimates battery self-discharge. bq2084 compensates charge-current measurement temperature battery state-of-charge. bq2084 also adjusts self-discharge estimation based temperature. main charge counter, RemainingCapacity() (RM), represents available capacity energy battery given time. bq2084 adjusts charge, self-discharge, other compensation factors. information register accessible through SMBus interface display.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
FullChargeCapacity() (FCC) register value represents last measured learned full discharge battery. used battery full-charge reference relative capacity indication. bq2084 updates after battery undergoes qualified discharge from nearly-full low-battery level. accessible through SMBus interface. Discharge Count Register (DCR) non-accessible register that tracks battery discharge. bq2084 uses register update register battery undergoes qualified discharge from nearly-full low-battery level. this way, bq2084 learns true discharge capacity battery under system conditions. Main Gas-Gauge Registers RemainingCapacity() (RM) represents remaining capacity battery. bq2084 computes units either depending selected mode. Battery Mode() (0x03) Table units configuration. counts during charge maximum value FullChargeCapacity() (FCC) down during discharge self-discharge minimum addition charge self-discharge compensation, bq2084 calibrates three low-battery-voltage thresholds, EDV2, EDV1, EDV0 three programmable midrange thresholds VOC25, VOC50, VOC75. This provides voltage-based calibration counter. DesignCapacity() (DC) user-specified battery-full capacity. calculated from Pack Capacity 0x32-0x33) represented units mWh. also represents full-battery reference absolute display mode. FullChargeCapacity() (FCC) last learned measured discharge capacity battery. represented units either mWh, depending selected mode. initialization, bq2084 sets value stored Full Charge Capacity 0x36-0x37). During subsequent discharges, bq2084 updates with last learned measured discharge capacity battery. last learned measured discharge battery based value Discharge Count Register (DCR) after qualified discharge occurs. Once updated, bq2084 writes value data flash Full Charge Capacity. represents full battery reference relative display mode, relative state charge AtRate() calculations. Discharge Count Register (DCR) register counts during discharge, independent counts discharge activity, battery load estimation, self-discharge increments. bq2084 initializes DCR, beginning discharge, when within programmed value Near Full 0x30. initial value reduced FCC/128 (bit Gauge Configuration), reduced stops counting when battery voltage reaches EDV2 threshold discharge. Capacity Learning (FCC Update) Qualified Discharge bq2084 updates with amount based value qualified discharge occurs. value equals value plus programmable nearly-full low-battery levels, according following equation: (new) (final) (initial) Measured Discharge EDV2 (FCC Low%) Battery (value stored 0x2f) 2.56 qualified discharge occurs battery discharges from Near Full EDV2 voltage threshold with following conditions: more than self-discharge battery load estimation occurs during discharge period. temperature does drop below temperature threshold programmed Learning Temp 0xach time when EDV2 reached. battery voltage reaches EDV2 threshold during discharge period, voltage greater than equal EDV2 threshold minus when bq2084 detected EDV2. midrange voltage correction occurs during discharge period.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Current remains 3C/32 when EDV2 Battery level reached. overload condition exists when EDV2 threshold reached RM() dropped Battery Low% FCC. valid charge activity occurs during discharge period. valid charge defined uninterrupted charge into battery.
bq2084 sets PackStatus() when qualified discharge begins. bq2084 sets disqualifying condition occurs. cannot reduced more than increased more than during single update cycle. bq2084 saves value data flash within seconds being updated. End-of-Discharge Thresholds Capacity Correction bq2084 monitors battery three low-voltage thresholds, EDV0, EDV1, EDV2. thresholds programmed determination based overall pack voltage individual cell level. EDVV Pack Configuration 0x28 configures bq2084 overall voltage single-cell thresholds. programmed single cell determination, bq2084 determines basis lowest single-cell voltage. Fixed thresholds must programmed EMF/EDV0 0x95-0x96, Factor/EDV1 0x97-0x98 Factor/EDV2 0x99-0x9a. CEDV Gauge Configuration 0x29 set, automatic compensated EDVs enabled bq2084 computes EDV0, EDV1, EDV2 voltage thresholds based values 0x95-0xa0 battery's current discharge rate temperature. bq2084 disables detection Current() exceeds Overload Current threshold programmed 0x5b-DF 0x5c. bq2084 resumes threshold detection after Current() drops below Overload Current threshold. threshold detected reset after charge detected cleared after charge. bq2084 uses thresholds apply voltage-based corrections register according Table Table State Charge Based Battery Voltage
THRESHOLD EDV0 EDV1 EDV2 RELATIVE STATE CHARGE Battery
bq2084 performs EDV-based adjustments with Current() C/32. flags current C/32. bq2084 adjusts detects each threshold. voltage threshold reached before corresponding capacity discharge, bq2084 reduces appropriate amount shown Table level reached discharge before voltage reaches corresponding threshold, then held that level until threshold reached. only held indicating valid learning cycle progress. Battery zero, EDV1 EDV0 corrections disabled. Thresholds Near-Full Programming bq2084 uses values stored data flash EDV0, EDV1, EDV2 values calculates three thresholds from base value temperature, capacity, rate adjustment factors stored data flash. compensation disabled, then EDV0, EDV1, EDV2 stored directly 0x95-0x96, 0x97-0x98, 0x99-0x9a, respectively. capacity correction EDV2, Battery 0x2f) desired state-of-charge, STATEOFCHARGE%, range 3-19%. Typical values STATEOFCHARGE% 5-7%, representing 5-7% capacity. Battery (STATEOFCHARGE% 2.56) bq2084 updates qualified discharge occurs from near-full threshold Near Full, until EDV2 condition reached. desired near-full threshold window programmed Near Full 0x30, 0x31 mAh.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Discharge Rate Temperature Compensation Programming compensation enabled, bq2084 calculates battery voltage determine EDV0, EDV1, EDV2 thresholds function battery capacity, temperature, discharge load. general equation EDV0, EDV1, EDV2 calculation EDV0,1,2 (EMF |ILOAD| FTZ) no-load cell voltage higher than highest cell threshold computed. programmed EMF/EDV1 0x95-0x96). ILOAD current discharge load magnitude. number series cells. factor that adjusts voltage battery capacity temperature match no-load characteristics battery. (either Battery EDV0, EDV1, EDV2, respectively) capacity related adjustment factors. programmed Factor/EDV1 0x97-98). desired residual battery capacity remaining EDV0 factor stored Factor 0xa0). current temperature represents resistance cell function temperature capacity. first order rate dependency factor stored Factor/EDV2 0x99-0x9a). current temperature; battery capacity relating EDV0, EDV1, EDV2. adjusts variation impedance with battery capacity. programmed Rate Factor 0x9d-0x9e). adjusts variation impedance with battery temperature. programmed Rate Factor 0x9b-0x9c). adjusts variation impedance cold temperatures 23°C). programmed 0x9f). Typical values compensation factors, based overall pack voltages Li-lon 3s2p 18650 pack, are: 11550/3 4475 Table bq2084 Register Functions
FUNCTION ManufacturerAccess RemainingCapacityAlarm RemainingTimeAlarm BatteryMode AtRate AtRateTimeToFull COMMAND CODE 0x00 0x01 0x02 0x03 0x04 0x05 ACCESS Read/write Read/write Read/write Read/write Read/write Read mAh, minutes minutes UNITS
5350/3
Command codes expressed numbers.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table bq2084 Register Functions (continued)
FUNCTION AtRateTimeToEmpty AtRateOK Temperature Voltage Current AverageCurrent MaxError RelativeStateOfCharge AbsoluteStateOfCharge RemainingCapacity FullChargeCapacity RunTimeToEmpty AverageTimeToEmpty AverageTimeToFull ChargingCurrent ChargingVoltage Battery Status CycleCount DesignCapacity DesignVoltage SpecificationInfo ManufactureDate SerialNumber Reserved ManufacturerName DeviceName DeviceChemistry ManufacturerData Pack status Pack configuration VCELL4 VCELL3 VCELL2 VCELL1 VPACK AFEData COMMAND CODE 0x06 0x07 0x08 0x09 0x0a 0x0b 0x0c 0x0d 0x0e 0x0f 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d-0x1f 0x20 0x21 0x22 0x23 0x2f (LSB) 0x2f (MSB) 0x3c 0x3d 0x3e 0x3f 0x45 0x46 Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read Read ACCESS UNITS minutes Boolean 0.1°K percent percent percent mAh, mAh, minutes minutes minutes cycles mAh, integer string string string string
Self-Discharge bq2084 estimates self-discharge battery maintain accurate measure battery capacity during periods inactivity. bq2084 makes self-discharge adjustments every when awake periodically (determined Sleep Timer 0xfe) when sleep mode. self-discharge estimation rate 25°C doubled each degrees above 25°C halved each degrees below 25°C. Table shows relation self-discharge estimation given temperature rate programmed 25°C programmed 0x2d).
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table Self-Discharge Rate Programmed
TEMPERATURE (°C) Temp Temp Temp Temp Temp Temp Temp Temp SELF-DISCHARGE RATE 16Y% 32Y%
nominal self-discharge rate, %PERDAY day), programmed 8-bit value Self-Discharge Rate 0x2d) following relation: Self-Discharge Rate %PERDAY 0.01 Battery Electronic Load Compensation bq2084 configured compensate constant load from battery electronics) present battery pack times. bq2084 applies compensation continuously when charge discharge below digital filter. bq2084 applies compensation (BEL) addition self-discharge. compensation occurs rate determined value stored Electronics Load 0x2e). compensation range µA-765 steps approximately data stored follows: Electronics Load Midrange Capacity Corrections bq2084 applies midrange capacity corrections when VCOR Gauge Configuration 0x29). bq2084 adjusts associated percentage three different voltage levels: VOC25, VOC50, VOC75. values represent open circuit battery voltage which corresponds associated percentage each threshold. midrange corrections occur, temperature must range 19°C 31°C inclusive Current() AverageCurrent() must both report between bq2084 makes midrange corrections shown table below. correction occur, bq2084 must detect need correction twice during subsequent 20-s intervals. With VCOR set, bq2084 makes midrange corrections whenever conditions permit. OTVC Gauge Configuration 0x29) VCOR bq2084 makes Voltage() measurements, determines average readings sets appropriate level. further RSOC% Voltage() validation performed until after next device reset. Table Midrange Corrections
CONDITION VOC75 RelativeStateOfCharge() VOC75 RelativeStateOfCharge() Voltage() VOC50 RelativeStateOfCharge() <VOC50 RelativeStateOfCharge() VOC25 RelativeStateOfCharge() VOC25 RelativeStateOfCharge() RESULT RelativeStateOfCharge() RelativeStateOfCharge() RelativeStateOfCharge() RelativeStateOfCharge() RelativeStateOfCharge() RelativeStateOfCharge()
Three voltage-based thresholds, VOC25 0x88-0x89), VOC50 0x83-0x84), VOC75 0x7e-0x7f), stored data flash
Charge Control
bq2084 internal charge control compatible with constant current/constant voltage profile Li-Ion. bq2084 detects primary charge termination basis tapering charge current during constant-voltage phase.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Charging Voltage Broadcasts bq2084 supports charge control broadcasting ChargingCurrent() ChargingVoltage() Smart Charger address. bq2084 broadcasts requests every seconds. bq2084 updates values used charging current voltage broadcasts based battery's state charge, voltage, temperature. 16-bit value (mV) charging voltage programmed Charging Voltage 0x03a-0x3b) although different operating conditions. also sets base value determining overvoltage conditions during charging voltage compliance during constant-voltage charging methodology. 16-bit value, Over Voltage Margin 0x5d-0x5e), sets limit over ChargingVoltage() that considered overvoltage charge-suspension condition. Charging Current Broadcasts ChargingCurrent() values either broadcast Level smart battery charger read from bq2084 Level-3 smart battery charger. ChargingCurrent() take four different values: Fast-Charging Current 0x3e-0x3f), Maintenance Charging Current 0x40-0x41), Precharge Current (0x42-0x43) depending charge state operating conditions. When fast charge allowed, bq2084 sets ChargingCurrent() rate programmed Fast-Charging Current 0x3e-0x3f). Fast-Charging Current stored When fast charge terminates, bq2084 sets ChargingCurrent() zero then MaintenanceCharging Current 0x40-0x41) when termination condition ceases. desired maintenance current stored When Voltage() less than EDV0, bq2084 sets ChargingCurrent() Precharge Current 0x42-0x43). Typically, this rate larger than maintenance rate charge deeply depleted pack point where fast charged. desired precharge rate stored temperature between Charge Inhibit Temp 0x46) precharge threshold (°C), bq2084 sets ChargingCurrent() PreCharge Current. threshold programmed Precharge Temp 0x44). maximal value precharge temperature threshold setting 12.7°C. Precharge Temp (°C) bq2084 also sets ChargingCurrent() precharge rate Voltage() less than value programmed Precharge Voltage 0x3ch-0x3d). Precharge Voltage programmed Alarm Broadcasts Smart Charger Host bits 8-15 BatteryStatus() set, bq2084 broadcasts AlarmWarning() message Host address. bits 12-15 BatteryStatus() set, bq2084 also sends AlarmWarning() message Smart Charger address. bq2084 repeats AlarmWarning() messages every seconds until alarm bits cleared. broadcasts disabled setting (bit Pack Configuration 0x28). Precharge Qualification bq2084 sets ChargingCurrent() precharge rate programmed Precharge Current 0x42-0x43) under following conditions: Voltage: bq2084 requests precharge charge rate when cell voltage drops below precharge threshold, when EDV0 threshold detected. Once requested, precharge rate remains until cell voltages increase above precharge threshold EDV0 condition does exist. precharge threshold programmed Precharge Voltage 0x3c-0x3d). Temperature: bq2084 requests precharge rate when Temperature() between Charge Inhibit Temp 0x46) precharge threshold programmed Precharge Temp 0x44). Temperature() must equal greater than precharge threshold allow fast-charge rate. Charge Suspension bq2084 temporarily suspend charging detects charging fault. charging fault includes following conditions.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Overcurrent: overcurrent condition exists when bq2084 measures charge current greater than Charge Threshold 0x12a-0x12b) time greater than Charge Time 0x12c). detecting overcurrent condition, bq2084 turns Charge FET. Nonremovable Battery Misc Configuration 0x2a), then Discharge turned also. This condition cleared when pack removed Nonremovable Battery Misc Configuration 0x2a) when discharge current detected when AverageCurrent() less than ClearFailCurrent 0x61-0x62) FaultResetTime 0x130). Overtemperature: During charging, overtemperature condition exists when Temperature() greater than Charge Suspend Temp High value programmed 0x6dh, 0x6eh. detecting overtemperature condition, enabled Misc Configuration 0x2a), bq2084 turns Charge Discharge FETs. overtemperature condition cleared when Temperature() equal below Charge Suspend Temp High Reset 0x6f-0x70). condition also cleared pack removed. Undertemperature: During charging, undertemperature condition exists when Temperature() less than Charge Suspend Temp 0x79), Charge Inhibit Temp 0x46). detecting undertemperature condition bq2084 turns Charge FET. undertemperature condition cleared when Temperature() greater than Charge Suspend Temp 0x79). condition also cleared pack removed. maximal value Charge Suspend Temp setting 12.7°C. Maximum Charging Time exceeded: Charging exceeds Maximum Charging Time 0x10f-0x110). charging time reaches Maximum Charge Time, Charge turned off. This condition cleared when pack detects discharge current removed. Cell Pack Overvoltage: overvoltage condition exists when cell greater than Cell Over Voltage Limit 0x63h-0x64h) Voltage() greater than Charging Voltage 0x3a-0x3b) plus OvervoltageMargin 0x5d-05e). This condition cleared when pack removed Nonremovable Battery Misc Configuration 0x2a), when discharge current detected when AverageCurrent() less than ClearFailCurrent 0x61-0x62) FaultResetTime 0x130). Also, overvoltage conditon must cleared Voltage() less than Charging Voltage 0x3a-0x3b) plus OvervoltageMargin 0x5d-05e) cell voltages less than Cell Over Voltage Reset 0xe0-0xe1). Pulse charging: Charging also temporarily suspended during pulse-charging, this considered fault condition.
Pulse Charge bq2084 pulse-charging algorithm, allowing charge control systems where charger does control current. pulse-charging algorithm uses voltage thresholds associated time limits control. These stored constants data flash. cell voltages read converter every during charging. voltage used comparison thresholds highest cell voltage. These thresholds three data flash constants: Charge Voltage, Voff Charge Voltage, Vmax Charge Voltage. Charge Voltage lowest these, threshold below which charge turned provided minimum time (Pulse Minimum Time) been met. When voltage crosses Voff threshold, maximum time (Pulse Maximum Time) begins count down. When this time expired, charge turned off. time Vmax exceeded, charge turned immediately. rules are: charge voltage above Vmax, turn off. Else voltage above Voff time expired, turn off. Else count down time charge off: voltage below minimum time, turn Else increment time. Voltage sampled every therefore, minimum time maximum time units pulse times integral multiples
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
voltage thresholds chosen such that they alter charge mechanism. Voff equal Vmax, then every time this threshold crossed, charge turns immediately. This effectively disables maximum charge time, that Voff threshold effect. this case, algorithm described having voltage thresholds, rather than three. charge simply turns crosses thresholds. minimum time similarly disabled setting zero one. sample interval, charge always least 125-ms cycle. Thresholds must chosen carefully obtain desired charging behavior. example, value less than charge voltage minus taper voltage, pack never detect full charge. During pulse charging, charge remains until cells relax values less voltage, which below qualification voltage full charge detection. During on-cycle phase pulse charging (charge ON), voltage exceed Voff value period until next sample taken switched OFF. prevent cell overvoltage termination, pack overvoltage termination during this period, values cell should higher than voltage reached during this period. reasonable value cell given charger current calculated, assuming cell impedance 0.08 /cell, calculated V(cell)OV 0.08 Correspondingly, pack overvoltage margin should value calculated V(margin) V(cell)OV V(charge) where: number series cells. When charging begins depleted battery pack, voltage below Voff, even stay below some time. This means pack under constant charge, with pulsing, some part charge cycle. voltage cells rises, crosses Voff threshold Vmax threshold Voff disabled), charge turns off. Initially, time short, since cell voltages only barely over threshold, quickly relax below Von. cell voltages rise, times become longer times shorter. This effect, combination with reduced current drawn cells, results gradually declining charge current. Eventually, this current falls below taper current, pack detects full charge condition stops charging. pulse-charging control operates during normal charging conditions overridden fault condition occurs. Charging stopped fault conditions such overtemperature overcurrent, without regard voltage thresholds time limits. Primary Charge Termination bq2084 terminates charge detects charge-termination condition based current taper. charge-termination condition includes following: bq2084 detects current taper termination when pack voltage greater than Charging Voltage 0x3a-0x3b) minus Current Taper Qualification Voltage 0x4d-0x4e) AverageCurrent() below Current Taper Threshold 0x4b-0x4c), greater than Charge Detection Current 0x113-0x114), period Current Taper Window 0x4f). Once bq2084 detects Primary Charge Termination, bq2084 sets TERMINATE_CHARGE_ ALARM FULLY_CHARGED bits BatteryStatus(), turns charge bq29312. charge turned when discharge current detected greater than Discharge Detection Current 0x115-0x116), minimize losses. TERMINATE_CHARGE_ ALARM charge current longer detected pack removed, returns charging attempted while FULLY_CHARGED set. bq2084 clears FULLY_CHARGED when RelativeStateOfCharge() less than programmed Fully Charged Clear Table summary BatteryStatus() alarm status operation. Cell Balancing bq2084 balances cells during charge discharging those cells above threshold Cell Balance Threshold 0xe8-0xe9), maximum difference cell voltages exceeds value programmed Cell
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Balance 0xec). cell balancing, bq2084 measures cell voltages interval Cell Balance Interval 0xed). basis cell voltages, bq2084 either selects appropriate cell discharge adjusts cell balance threshold value programmed Cell Balance Window 0xea-0xeb) when cells exceed cell balance threshold highest cell exceeds cell balance threshold cell balance window. cell balance threshold reset value Cell Balance Threshold start every charge cycle. threshold only adjusted once during balance interval. cells severely imbalanced during charging, where VCELL(MAX)- VCELL(MIN) Cell Imbalance Threshold, then Status set. Table Cell Balancing Programming
NAME Cell Balance Threshold Cell Balance Cell Balance Window Cell Balance Interval Cell Imbalance Threshold Location 0xe8-0xe9 0xec 0xea-0xeb 0xed 0xee-0xef DESCRIPTION Sets maximum voltage that each cell must achieve initiate cell balancing. Programming Cell Balance Threshold 65,535 disables cell balancing. Sets cell differential that must exist initiate cell balancing Sets amount that cell balance threshold increase Sets cell-balancing time interval seconds. Sets severe imbalance fault limit
DISPLAY PORT
General display port drives 5-LED bar-graph display. display activated logic signal DISP input. bq2084 display either relative absolute mode with each representing percentage full-battery reference. relative mode, bq2084 uses full-battery reference; absolute mode, uses Design Capacity (DC). DMODE Pack Configuration 0x28) programs bq2084 absolute relative display mode. bits program 5-LED option. Activation display activated time high-to-low transition DISP input. This usually accomplished with pullup resistor pushbutton switch. Detection transition activates display starts display timer. Reactivation display requires that DISP input return logic-high state then transition again. second high-to-low transition detected only after display timer expires. unused, DISP input must pulled VCC. EDV0 set, bq2084 disables display. Display Modes relative mode, each output represents 20%, 25%, RelativeStateOfCharge() value. absolute mode, each output represents 20%, AbsoluteStateOfCharge() value. Table shows display options LEDs, Table LEDs, Table LEDs. either mode, bq2084 blinks display RemainingCapacity() less than Remaining CapacityAlarm(). display disabled EDV0 Table Display Mode Five LEDs
CONDITION RELATIVE ABSOLUTE StateOfCharge() EDV0 <20% 20%, 40%, 60%, LED1 FIVE-LED DISPLAY OPTION LED2 LED3 LED4 LED5
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table Display Mode Four LEDs
CONDITION RELATIVE ABSOLUTE StateOfCharge() EDV0 <25% 25%, 50%, LED1 FOUR-LED DISPLAY OPTION LED2 LED3 LED4
Table Display Mode Three LEDs
CONDITION RELATIVE ABSOLUTE StateOfCharge() EDV0 <34% 34%, LED1 THREE-LED DISPLAY OPTION LED2 LED3
Li-Ion Protective Safety Features
bq2084 conjunction with bq29312 provides protective safety features Li-Ion batteries, shown Table bq2084 measures temperature current uses bq29312 measure individual cell voltage. bq2084 uses this information determine protection requirements, control safety FETs SAFE output necessary. recommended that bq2084 protection control validated successive measurements setting Misc Configuration. bq29312 independently detect protect load from overload (OL) short circuit charge (SCC) discharge (SCD). bq29312 sets appropriate state then alerts bq2084 with XALERT output when ever protection threshold breached associated delay time expired. bq2084 then determines when FETs should turned back Table CVOV CVUV Flags PackStatus()
FLAG CONDITION
CLEAR CONDITION (see Note Voltage() ChargingVoltage() VCELL(ALL) Cell Over Voltage Reset VCELL(ALL) Cell Under Voltage Reset
(1))
Voltage() ChargingVoltage() Over Voltage CVOV Margin VCELL(ANY) Cell Over Voltage CVUV VCELL(ANY) Cell Under Voltage AverageCurrent() Over Load Current
AverageCurrent() Current Fault Clear Threshold
Clear detected controlled bq2084. there discharge current there charge current
Protection Configuration
Level Cell Voltage Thresholds cell undervoltage (VUV) overvoltage (VOV) limits programmed Cell Under Voltage Cell Over Voltage 0x65-0x66, 0x63-0x64, respectively). Both values stored Cell Over Voltage Reset 0xe0-0xe1) Cell Under Voltage Reset 0xe2-0xe3) reset points these safety parameters. Safety Overvoltage Threshold safety voltage threshold programmed Safety Over Voltage 0x6b-0x6c), stored Exceeding this value triggers permanent failure enabled PFConfig.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Overcurrent Thresholds Discharge current threshold programmed Discharge Threshold 0x12d-0x12e). discharge overcurrent must exist time programmed Discharge Time 0x12f). When discharge-overcurrent condition detected, discharge turned off. Similarly, charge overcurrent programmed Charge Threshold 0x12a-0x12b). charge overcurrent must exist time programmed Charge Time 0x12c) Charge Time 0x12c). When charge overcurrent condition detected charge turned off. Temperature Thresholds Safety Over Temperature Charge (SOTC) threshold programmed Safety Over Temperature Charge 0x75-0x76) Safety Over Temperature Discharge (SOTD) threshold programmed Safety Over Temperature Discharge 0x77-0x78). SOTC stored Safety Over Temperature Charge SOTC (°C) unsigned integer SOTD stored Safety Over Temperature Discharge SOTD (°C) unsigned integer. Exceeding Safety Temperatures causes permanent failure enabled PFConfig. There also temperature thresholds disable both charge discharge FETs Battery Status Overtemperature bit. thresholds according whether discharge charging detected. Charge Suspend Temp High threshold stored 0x6d-0x6e with reset threshold stored 0x6f-0x70. Likewise Over Temperature Discharge threshold stored 0x71-0x72 with reset threshold stored 0x73-0x74. Charge Suspend Temp threshold (CSTL) stored Charge Suspend Temp 0x79-0x7a) stored Charge Suspend Temp CSTL (°C) signed integer. Charge Suspend Temp turns charge FET. maximal value Charge Suspend Temp setting 12.7 Configuration protection limits programmed specified bq29312 data sheet. Over Load 0xc5) sets overload protection threshold. Over Load Delay 0xc6) sets delay timing overload protection. Short Circuit Charge 0xc7) sets short circuit charge protection threshold delay time. Short Circuit Discharge 0xc8) sets short circuit discharge protection threshold delay time. SMBus command 0x46 used string read with address 0x00 first, bq2084 sealed indicated PackStatus. Table Overcurrent Protection
FAILURE ZVCHG off, off, ZVCHG off, Same Average Current Clear Fail Current 0x61/2) Fault Reset Time 0x130), disharge current discharge detection current 0x115/6) Average Current -Clear Fail Current 0x61/2) Fault Reset Time 0x130), charge current charge detection current 0x113/4) Same Same STATUS CLEAR CONDITIONS
Charge (set 0x12a 0x12c) Discharge (set 0x12d 0x12f) FAILURE
ZVCHG off, off, ZVCHG off, ZVCHG off,
STATUS FETs FETs RRES high PRES high
EXIT CONDITIONS
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table Overcurrent Protection (continued)
FAILURE Charge (set 0x12a 0x12c) Discharge (set 0x12d 0x12f) FETs FETs FETs PRES high PRES high PRES high STATUS CLEAR CONDITIONS
Integrity Check bq2084 checks programming registers period determined Check Time 0xfb). units check period seconds unless bq2084 sleep mode, which case period Check Time Current Multiplier 0xfd). data correct, bq2084 increments internal counter until reaches Fail Limit 0xe4). Setting Check Time disables this function. When internal Fail counter reaches Fail Limit, Status set. Watchdog Fault Clear bq29312 feature where output (CLKOUT, bq2084 used drive internal clock. this clock fails, fault declared AFE. bq29312 data sheet, literature number SLUS546E, further details. fault cleared automatically return 32-kHz input bq2084 CLKOUT pin. Permanent Failure Mode (SAFE Output) SAFE output bq2084 provides additional level safety. active safety output blow fuse control another switch basis temperature, pack-voltage, cell-voltage, failure, severe cell imbalance, integrity check Data Flash configuration registers. bq2084 also activate SAFE output Flag based PFIN input. this PFIN Time seconds then PFIN Status set. SAFE output driven following conditions bq2084 sets Flag register 0x11e) 0x66 1100 1100). activation SAFE output setting Flag enabled disabled meet different safety requirements specified Config 0x11f) register settings. SAFE output Flag register only cleared using series ManufacturerAccess() commands. Table SAFE Activation Conditions
CONDITION Voltage() Safety Over Voltage 0x6b 0x6c), Temperature() Safety Over Temperature Charge 0x75 0x76) Temperature() Safety Over Temperature Discharge 0x77 0x78) When Miscellaneous Configuration (0x2a) set, number failures reached Fail Limit 0xe4) When VCELL(MAX) VCELL(MIN) Cell Imbalance Threshold 0xee, 0xef) during charging charge off, charge current greater than Fail charge current stored 0x125-0x126 time determined Fail time 0x129, discharge discharge current greater than Fail discharge current stored 0x127-0x128 time determined Fail time 0x129. PFIN input detected state PFIN Time consecutive seconds, determined 0x120 SAFE output activated Flag only enabled Config 0x0x11f) ACTIONS SOTC SOTD FETF andPF
PFIN,
Permanent Failure Status Status)
Status 0x11d contains flags cause permanent failure mode.
PFIN FETF SOTD SOTC
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
indicates safety overvoltage occurred, which enabled Config, would cause SAFE output activate. SOTC SOTC indicates safety overtemperature charge occurred, which enabled Config, would cause SAFE output activate. SOTD SOTD indicates safety overtemperature discharge occurred, which enabled Config, would cause SAFE output activate. indicates integrity fault state occurred, which enabled Config, would cause SAFE output activate. indicates that severe cell imbalance occurred during charging, which enabled Config, would cause SAFE output activate. FETF FETF indicates driver failure occurred, which enabled Config, would cause SAFE output activate. PFIN PFIN used indicate that output level protector activated. used indicate that current been detected when fuse been blown. Current detected with fuse blown Current detected with fuse blown PFIN input high (default) PFIN input drive held level protector output FETs operating normally (default) FETs drivers have fault cells within Cell Imbalance Threshold (default) There severe cell imbalance operating correctly (default) Integrity check fail limit reached SOTD fault detected (default) SOTD fault detected SOTC fault detected (default) SOTC fault detected fault detected (default) fault detected
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Permanent Failure Configuration Config)
Config 0x11f) contains enable/disable configuration that determines SAFE output activated Flag each possible failure mode.
XPFIN XFETF XCIM XAFE XSOTD XSOTC XSOV
XSOV XSOV enables disables activation SAFE setting Flag when Status set. XSOTC XSOTC enables disables activation SAFE setting Flag when Status SOTC set. XSOTD XSOTD enables disables activation SAFE setting Flag when Status SOTD set. XAFE XAFE enables disables activation SAFE setting Flag when Status set. Miscellaneous Config 0x2a) also must activation. XCIM XCIM enables disables activation SAFE setting Flag when Status set. XFETF XFETF enables disables activation SAFE setting Flag when Status FETF set. XPFIN XPFIN enables disables activation SAFE setting Flag when Status PFIN set. Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled Activation disabled (default) Activation enabled
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Permanent Failure Flag Flag)
Flag 0x11e) contains flag indicating SAFE output been activated.
STATE Clear
FLAG Flag indicates that SAFE output bq2084 been activated. 0x00 0x66 SAFE output high (default) SAFE output activated
example circuit using SAFE output blow fuse shown Figure
Figure Example SAFE Circuit Implementation
Low-Power Modes
bq2084 enters sleep mode when charge discharge current less than threshold programmed Sleep Current Threshold 0xfc), SMBus lines least Misc. Configuration 0x2a) zero. Additionally, PRES must pulled high Misc Config bq2084 wakes periodically monitor voltage temperature apply self-discharge adjustment. sleep period Sleep Timer 0xfe). bq2084 wakes period Sleep Current Multiplier 0xfd) Time measure current. bq2084 comes sleep when either SMBus lines high when current measured greater than Sleep Current Threshold. sleep current threshold, (mA), stored Sleep Current Threshold(DF 0xfc) Sleep Current Threshold SLP(mA) wake-up period current measurement, WAT(s), using following formula: Sleep Current Multiplier Time WAT(s) During sleep mode both charge discharge FETs turned Misc Config cleared. bq2084 Non-Removable mode where then discharge remains during sleep.
Shutdown Mode
bq2084 goes into shutdown, which FETs turned pack electronics powered down (including bq2084), when SBS.Voltage() falls below Shutdown Voltage 0x7c-0x7d) voltage Pack less than VPACK Threshold 0x131, 0x132). VPACK Threshold programmed units 0.935 mV/count, tolerance ±6%. example, VPACK Threshold, programmed value 12000 0.935 12834.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
When turned pack voltage very close battery voltage even with charger attached. Therefore, enter shutdown, VPACK Threshold should higher than shutdown threshold plus tolerance. bq2084 also instructed enter shutdown mode ManufacturerAccess() command. When command sent bq2084, bq29312 instructed enter shutdown mode bq2084. This forces chipset into lowest power mode. bq2084 does issue shutdown command unless pack voltage less than VPACK Threshold. Program VPACK Threshold higher than SBS.Voltage() when ship command issued. Exit from this mode only achieved connecting charger. After exiting shutdown mode, bq2084 does enter shutdown mode again until Shutdown Timer 0x133, units seconds) expired even correct conditions present. After Shutdown Timer expired, SMBus command voltage current conditions enables bq2084 enter shutdown mode.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Normal Operation SBS.VCELLx( Measured SBS.PackVoltage( Measured SBS.Voltage( calculated
SBS.Voltage( DF.Shutdown Threshold
SBS.Current(
SBS.PackVoltage( DF.Vpack Threshold
Time since exit from last Shutdown DF.Shutdown Timer?
bq2084 Enters Shutdown
Defaults Non-Removable Pack DF.ShutdownVoltage Number Series cells DF.ShutdownTimer Note: VpackThreshold must greater than Shutdown voltage Removable Pack DF.ShutdownVoltage Number Series cells DF.ShutdownTimer
Figure Shutdown Flow Chart Normal Operation
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
command 0x05 received
SBS.Current(
Pack voltage Vpack threshold
bq2084 Enters Shutdown
Figure Shutdown Flow Chart
Reset Conditions
power entire reset data loaded from Data Flash configure data battery-management system. partial reset (loss holds valid), following limited number actions taken: registers rewritten. PackStatus() EDV2 flag cleared. BatteryStatus() DISCHARGING flag cleared. charger alarm broadcast period seconds between broadcasts.
Communication
bq2084 includes SMBus communication port. SMBus interface 2-wire bidirectional protocol using SMBC (clock) SMBD (data) pins. communication lines isolated from pulled higher than VCC. Also, bq2084 does pull these lines part zero. communication ports allow host controller, SMBus compatible device, other processor access bq2084 memory registers. this system efficiently monitor manage battery.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
SMBus
SMBus interface command-based protocol. processor acting master initiates communication bq2084 generating start condition. start condition consists high-to-low transition SMBD line while SMBC high. processor then sends bq2084 device address 0001011 (bits 7-1) plus (bit followed SMBus command code. (LSB) command code instruct bq2084 either store forthcoming data register specified SMBus command code output data from specified register. processor completes access with stop condition. stop condition consists low-to-high transition SMBD line while SMBC high. With SMBus, most-significant (MSB) data byte transmitted first. some instances, bq2084 acts master. This occurs when bq2084 broadcasts charging requirements alarm conditions device addresses 0x12 (SBS Smart Charger) 0x10 (SBS Host Controller.) SMBus Protocol bq2084 supports following SMBus protocols: Read word Write word Block read processor acting master uses three protocols communicate with bq2084. bq2084 acting master uses write word protocol. SMBD SMBC pins open drain require external pullup resistors. pulldown resistor battery pack SMBC SMBD required assure detection SMBus off-state, performance automatic offset calibration, initiation low-power sleep mode when battery pack removed. SMBus Packet Error Checking bq2084 supports packet error checking mechanism confirm proper communication between another SMBus device. Packet error checking requires that both transmitter receiver calculate packet error code (PEC) each communication message. device that supplies last byte communication message appends message. receiver compares transmitted result determine there communication error. Protocol bq2084 receive transmit data with without PEC. Figure shows communication protocol read word, write word, read block messages without PEC. Figure includes PEC. read word protocol, bq2084 receives after last byte data from host. host does support PEC, last byte data followed stop condition. After receipt PEC, bq2084 compares value calculation. correct, bq2084 responds with ACKNOWLEDGE (ACK). correct, bq2084 responds with ACKNOWLEDGE (NACK) sets error code. write word block read, host generates after last byte data sent bq2084. bq2084 then sends PEC, host, acting master-receiver, generates NACK stop condition.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Gauge
Figure SMBus Communication Protocol Without
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Gauge
Figure SMBus Communication Protocol With Calculation basis calculation 8-bit cyclic redundancy check (CRC-8) based polynomial C(X) calculation includes bytes transmission, including address, command, data. calculation does include ACKNOWLEDGE, ACKNOWLEDGE, start, stop, repeated start bits. example, host requests RemainingCapacity() from bq2084. This includes host following read word protocol. bq2084 calculates based following bytes data, assuming remaining capacity battery 1001 mAh. Battery Address with 0x16 Command Code RemainingCapacity(): 0x0f Battery Address with 0x17 RemainingCapacity(): 0x03e9 0x160f17e903, bq2084 transmits 0xe8 host. Enable Master Mode master mode broadcasts charger, host, both enabled/disabled with combination bits Pack Configuration 0x28). SMBus Off-State bq2084 detects whether SMBus enters State monitoring SMBC SMBD lines. When both signals continually least bq2084 recognizes State. When SMBC SMBD lines high, bq2084 recognizes State begin communication within One-M pulldown resistors SMBC SMBD recommended reliable State detection.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Command Codes
SMBus command codes parentheses Temperature(), Voltage(), Current(), AverageCurrent(), performance specifications bq29312 regulated (V(REG)) temperature -20°C 85°C. Manufacturer Access() (0x00) Description: This function provides writable command codes control bq2084 during normal operation pack manufacture. Writing command code command 0x00 causes following reads with command 0x00 return word indicated Table following commands available: Table Manufacturer Access Commands
COMMAND CODE 0x0001 0x0002 0x0003 0x0004 0x0005 0x062b NAME Device Type Firmware Level Manufacturer Status SHIP Command Seal DESCRIPTION Returns part number read, i.e., 2084 (0x0824) Returns firmware version read Returns pending end-of-discharge voltage level read Returns battery system status read Instructs bq2084 instruct bq29312 enter ship mode Instructs bq2084 restrict access those functions listed Table bq2084 completes seal function clears ManufacturerAccess().
Manufacture Status word defined
FET1 FET0 STATE3 STATE2 STATE1 STATE0
FET1, FET0 Indicated state charge discharge FETs PF1, Indicates permanent failure cause when permanent failure indicated STATE3-STATE0 Fuse blown Cell imbalance failure Safety voltage failure failure Both charge discharge FETs Charge off, discharge Both charge discharge FETs off. Charge discharge off.
STATE3, STATE2, STATE1, STATE0 Indicates battery state defined State Status Summary. Purpose: ManufacturerAccess() function provides system host access bq2084 functions that defined SBD. SMBus protocol: Read write word Input/Output: Word
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table State Status Summary
State wakeup precharge chargesusp terminatecharge normalcharge provisionalcharge normaldischarge depleted depleted_ac overheatdischarge overheatcharge battfail_overcharge battfail_lowtemp battfail_chargeterminate battfail_afe_chg battfail_afe_dsg battfail_chg battfail_dsg removed sleep permanent_failure 0x08 Fault Charge Terminate 0x0c Battery Failure 0x0a Over Current 0x0f Battery 0x0d Sleep 0x09 Permanent Failure 0x0e System Present Mode (MSB) 0x00 Wake 0x03 Precharge 0x04 Charge suspension 0x07 Charge Terminate 0x05 Charge 0x01 Normal CC() CV()
ZVCHG off( (5))
FUSE blow
Power Mode normal normal normal normal normal normal normal normal normal normal normal normal normal normal normal normal normal normal normal
always discharge current greater than Discharge Detection Current 0x115, 0x116) Config (Common precharge, charge FET) ZVCHG Config (ZVCHG precharge FET) PC-precharge current, FC-fast charge current, CV-charge voltage ZVCHG Config (ZVCHG FET), ZVCHG off, Config (precharge FET) CVOV CVOV minimum cell voltage less than precharge cell voltage threshold MiscConfig.Nonremoveable Battery then
RemainingCapacityAlarm() (0x01) Description: Sets gets low-capacity threshold value. Whenever RemainingCapacity() falls below low-capacity value, bq2084 sends AlarmWarning() messages SMBus host with REMAINING_CAPACITY_ALARM set. low-capacity value disables this alarm. bq2084 initially sets Remaining Capacity Alarm 0x02-0x03) low-capacity value. This value remains unchanged until altered RemainingCapacityAlarm() function. low-capacity value expressed either current (mA) power mWh) depending setting BatteryMode() CAPACITY_MODE bit. Purpose: RemainingCapacityAlarm() function used systems capable estimating much power they require save their operating state. enables those systems more finely control point which they transition into suspend hibernate state. low-capacity value read verify value bq2084 low-capacity alarm. SMBus protocol: Read write word Input/Output: Unsigned integer-value below which Capacity messages sent.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Table Remaining Capacity Alarm Battery Modes
CAPACITY_MODE Units Range Granularity Accuracy 0-65,535 applicable RemainingCapacity() CAPACITY_MODE 0-65,535
RemainingTimeAlarm() (0x02) Description: Sets gets Remaining Time Alarm value. Whenever AverageTimeToEmpty() falls below remaining time value, bq2084 sends AlarmWarning() messages SMBus host with REMAINING_TIME_ALARM set. remaining time value effectively disables this alarm. bq2084 initially sets remaining time value Remaining Time Alarm value programmed 0x00-0x01. remaining time value remains unchanged until altered RemainingTimeAlarm() function. Purpose: RemainingTimeAlarm() function used systems that want adjust when remaining time alarm warning sent. remaining time value read verify value bq2084 RemainingTimeAlarm(). SMBus protocol: Read write word Input/Output: Unsigned integer-the point below which remaining time messages sent. Units: Minutes Range: 65,535 minutes Granularity: applicable Accuracy: AverageTimeToEmpty(). BatteryMode() (0x03) Description: Selects various battery operational modes reports battery's mode requests. Defined modes include Whether battery capacity information specified units (CAPACITY_MODE bit) Whether ChargingCurrent() ChargingVoltage() values broadcast smart battery charger when CHARGER_MODE set. Whether broadcasts smart battery charger host disabled defined request condition battery requesting conditioning cycle (RELEARN_FLAG). Purpose: CAPACITY_MODE allows power management systems best match their electrical characteristics with those reported battery. example, switching power supply represents constant power load, whereas linear supply better represented constant current model. CHARGER_MODE allows SMBus host smart battery charger override smart battery desired charging parameters disabling bq2084 broadcasts. RELEARN_FLAG allows bq2084 request conditioning cycle. SMBus protocol: Read write word Input/Output: Unsigned integer-bit mapped-see below. Units: applicable Range: Granularity: applicable Accuracy: applicable BatteryMode() word divided into halves, (bits 8-15) which read/write (bits 0-7) which read only. bq2084 forces bits zero prohibits writes Table summarizes meanings individual bits BatteryMode() word. Specified default values, where applicable, noted. INTERNAL_CHARGE_CONTROLLER used bq2084.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
PRIMARY_BATTERY_SUPPORT used bq2084. RELEARN_FLAG when indicates that bq2084 requesting capacity relearn cycle battery. bq2084 sets RELEARN_FLAG full reset detects 20-cycle counts without update. bq2084 clears this flag after learning cycle been completed. CHARGE_CONTROLLER_ENABLED used bq2084. bq2084 forces this zero. PRIMARY_BATTERY used bq2084. bq2084 forces this zero. Table Battery Mode Bits Values
BATTERY MODE() BITS INTERNAL_CHARGE_CONTROLLER PRIMARY_BATTERY_SUPPORT Reserved RELEARN_FLAG CHARGE_CONTROLLER_ENABLED PRIMARY_BATTERY Reserved ALARM_MODE CHARGER_MODE CAPACITY_MODE BITS USED 10-12 flag flag flag Read only flag flag flag FORMAT Read only flag Read only flag ALLOWABLE VALUES always always zero always zero 0-Battery OK1-Relearn cycle requested used used always zero 0-Enable alarm broadcast (default)1-Disable alarm broadcast 0-Enable charging broadcast (default)1-Disable charging broadcast 0-Report (default)1-Report
ALARM_MODE disable bq2084's ability master SMBus send AlarmWarning() messages SMBus host smart battery charger. When set, bq2084 does master SMBus, AlarmWarning() messages sent SMBus host smart battery charger period more than less than When cleared (default), smart battery sends AlarmWarning() messages SMBus host smart battery charger time alarm condition detected. ALARM broadcast does occur more often than once every Whenever BATTERY_MODE command received, bq2084 resets starts restarts 60-s (nominal) timer. After timer expires, bq2084 automatically enables alarm broadcasts ensure that accidental deactivation broadcasts does persist. SMBus host that does want bq2084 master SMBus must therefore continually this least once every keep bq2084 from broadcasting alarms. ALARM_MODE defaults cleared state when bq2084 enters SLEEP mode. condition ALARM-MODE does affect operation state CHARGER_MODE bit, which used prevent broadcasts ChargingCurrent() ChargingVoltage() smart battery charger. CHARGER_MODE enables disables bq2084's transmission ChargingCurrent() ChargingVoltage() messages smart battery charger. When set, bq2084 does transmit ChargingCurrent() ChargingVoltage() values smart battery charger. When cleared, bq2084 transmits ChargingCurrent() ChargingVoltage() values smart battery charger. CHARGER_MODE defaults cleared state when bq2084 enters SLEEP mode. CAPACITY_MODE indicates capacity information reported mA/mAh mW/10 mWh. When set, bq2084 reports capacity information mW/10 appropriate. When cleared, bq2084 reports capacity information mA/mAh appropriate. CAPACITY_MODE defaults cleared state when bq2084 enters SLEEP mode. following functions changed accept return values mA/mAh mW/10 depending CAPACITY_MODE bit: RemainingCapacityAlarm() AtRate() RemainingCapacity() FullChargeCapacity() DesignCapacity()
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
following functions calculated basis capacity calculated differently depending CAPACITY_MODE bit: AtRateOK() AtRateTimeToEmpty() AtRateTimeToFull() RunTimeToEmpty() AverageTimeToEmpty() AverageTimeToFull() Remaining Time Alarm() BatteryStatus() bq2084 updates non-AtRate related register values immediately after changing state CAPACITY_MODE bit. AtRate() values updated after next AtRate() value written bq2084 after next scheduled refresh calculation). AtRate() (0x04) Description: AtRate() function first half two-function call-set used AtRate value used calculations made AtRateTimeToFull(), AtRateTimeToEmpty(), AtRateOK() functions. AtRate value expressed either current (mA) power depending setting BatteryMode() CAPACITY_MODE bit. Purpose: Since AtRate() function first half two-function call-set, followed second function call-set that calculates returns value based AtRate value battery's present state. When AtRate() value positive, AtRateTimeToFull() function returns predicted time full-charge AtRate value charge. When AtRate() value negative, AtRateTimeToEmpty() function returns predicted operating time AtRate value discharge. When AtRate() value negative, AtRateOK() function returns Boolean value that predicts battery's ability supply AtRate value additional discharge energy (current power) seconds. default value AtRate() zero. SMBus protocol: Read write word Input/Output: Signed integer-charge discharge; AtRate() value positive charge, negative discharge, zero neither (default).
BATTERY MODES CAPACITY_MODE Units Charge range Discharge range Granularity Accuracy 32,767 -32,768 Unit CAPACITY_MODE 32,767 -32,768
AtRateTimeToFull() (0x05) Description: Returns predicted remaining time fully charge battery AtRate() value (mA). Purpose: AtRateTimeToFull() function part two-function call-set used determine predicted remaining charge time AtRate value bq2084 updates AtRateTimeToFull() within after SMBus host sets AtRate value. bq2084 automatically updates AtRateTimeToFull() based AtRate() value every SMBus protocol: Read word Output: Unsigned integer-predicted time minutes fully charge battery.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Units: Minutes Range: 65,534 Granularity: better Accuracy: |AtRate()| Invalid Data Indication: 65,535 indicates AtRate AtRateTimeToEmpty() (0x06) Description: Returns predicted remaining operating time battery discharged AtRate() value. Purpose: AtRateTimeToEmpty() function part two-function call-set used determine remaining operating time AtRate() value. bq2084 updates AtRateTimeToEmpty() within after SMBus host sets AtRate() value. bq2084 automatically updates AtRateTimeToEmpty() based AtRate() value every SMBus protocol: Read word Output: Unsigned integer-estimated operating time left. Units: Minutes Range: 65,534 Granularity: better Accuracy: -0,+ MaxError() FullChargeCapacity()÷ |AtRate()| Invalid Data Indication: 65,535 indicates AtRate AtRateOK() (0x07) Description: Returns Boolean value that indicates whether battery deliver AtRate() value additional energy AtRate() value zero positive, AtRateOK() function ALWAYS returns (logic Purpose: AtRateOK() function part two-function call-set used power management systems determine battery safely supply enough energy additional load. bq2084 updates AtRateOK() within after SMBus host sets AtRate() value. bq2084 automatically updates AtRateOK() based Rate() value every second. SMBus protocol: Read word Output: Boolean-indicates battery supply additional energy requested. Units: Boolean Range: Granularity: applicable Accuracy: applicable Temperature() (0x08) Description: Returns temperature measured bq2084. Purpose: Temperature() function provides accurate cell temperatures battery chargers thermal management systems. battery charger temperature safety check. Thermal management systems temperature because battery largest thermal sources system. SMBus protocol: Read word Output: Unsigned integer-cell temperature tenth-degree Kelvin increments. Units: 0.1°K
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Range: +6553.5°K {real range} Granularity: 0.1°K Accuracy: ±1.5°K (from ideal Semitec 103AT thermistor performance, after calibration) Voltage() (0x09) Description: Returns cell-pack voltage (mV). Purpose: Voltage() function provides power management systems with accurate battery-terminal voltage. Power management systems this voltage, along with battery current information, characterize devices they control. This ability helps enable intelligent, adaptive power-management systems. SMBus protocol: Read word Output: Unsigned integer-battery terminal voltage Units: Range: 20,000 Granularity: Accuracy: ±0.25% (after calibration) Current() (0x0a) Description: Returns current being supplied accepted) battery (mA). Purpose: Current() function provides snapshot power management system current flowing into battery. This information particular power-management systems because they characterize individual devices tune their operation actual system power behavior. SMBus protocol: Read word Output: Signed integer-charge/discharge rate increments: positive charge, negative discharge. Units: Range: -32,768 32,767 Granularity: Accuracy: 0.25% whichever greater AverageCurrent() (0x0b) Description: Returns value that approximates one-minute rolling average current being supplied accepted) through battery terminals (mA). AverageCurrent() implemented single pole filter with 14.5-s time constant. Purpose: AverageCurrent() function provides average current flowing into battery power management system. SMBus protocol: Read word Output: Signed integer-charge/discharge rate increments: positive charge, negative discharge. Units: Range: -32,768 32,767 Granularity: Accuracy: 0.25% whichever greater
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
MaxError() (0x0c) Description: Returns expected margin error state charge calculation. example, when MaxError() returns RelativeStateOfCharge() returns 50%, RelativeStateOfCharge() more likely between 60%. bq2084 sets MaxError() 100% full reset. bq2084 sets MaxError() completion learning cycle, unless bq2084 limits learning cycle +512/-256 maximum adjustment values. learning cycle limited, bq2084 sets MaxError() unless MaxError() already below this case, MaxError() does change. bq2084 increments MaxError() after four increments CycleCount() without learning cycle. voltage-based corrections applied coulomb counter, MaxError() 25%. Purpose: MaxError() function real value ways: first, give user confidence level about state charge second, give power management system information about aggressive should particularly battery nears life. SMBus protocol: Read word Output: Unsigned integer-percent uncertainty selected information. Units: Range: 2-100% Granularity: Accuracy: applicable RelativeStateOfCharge() (0x0d) Description: Returns FullChargeCapacity() (%). predicted remaining battery capacity expressed percentage
Purpose: RelativeStateOfCharge() function used estimate amount charge remaining battery relative last learned capacity. SMBus protocol: Read word Output: Unsigned integer-percent remaining capacity. Units: Range: 0-100% Granularity: Accuracy: +MaxError() AbsoluteStateOfCharge()(0x0e) Description: Returns predicted remaining battery capacity expressed percentage DesignCapacity() (%). Note that AbsoluteStateOfCharge() return values greater than 100%. Purpose: AbsoluteStateOfCharge() function used estimate amount charge remaining battery relative nominal DesignCapacity(). SMBus protocol: Read word Output: Unsigned integer-percent remaining capacity. Units: Range: 0-100+% Granularity: Accuracy: +MaxError() RemainingCapacity() (0x0f) Description: Returns predicted charge energy remaining battery. RemainingCapacity() value expressed either charge energy, depending setting BatteryMode() CAPACITY_MODE bit.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Purpose: RemainingCapacity() function returns battery's remaining capacity. This information numeric indication remaining charge energy given Absolute Relative StateOfCharge() functions better form power management systems. SMBus protocol: Read word Output: Unsigned integer-remaining charge units mWh.
BATTERY MODES CAPACITY_MODE Units Range Granularity Accuracy 0-65,535 +MaxError() CAPACITY_MODE 0-65,535 FullCharageCapacity()
FullChargeCapacity() (0x10) Description: Returns predicted pack capacity when fully charged. FullChargeCapacity() value expressed either current (mAh discharge rate) power discharge rate) depending setting BatteryMode() CAPACITY_MODE bit. Purpose: FullChargeCapacity() function provides means understanding 'tank size' battery. This information, along with information about original capacity battery, indicates battery wear. SMBus protocol: Read word Output: Unsigned integer-estimated full-charge capacity units mWh.
BATTERY MODES CAPACITY_MODE Units Range Granularity Accuracy 0-65,535 CAPACITY_MODE 0-65,535
+MaxError() FullCharageCapacity()
RunTimeToEmpty() (0x11) Description: Returns predicted remaining battery life present rate discharge (minutes). RunTimeToEmpty() value calculated based either current power depending setting BatteryMode() CAPACITY_MODE bit. Purpose: RunTimeToEmpty() function provides power management system with information about relative gain loss remaining battery life response change power policy. This information same AverageTimeToEmpty(), which suitable determine effects that result from change power policy. SMBus protocol: Read word Output: Unsigned integer-minutes operation left. Units: Minutes Range: 65,534 Granularity: better Accuracy: Invalid Data Indication: 65,535 indicates battery being discharged.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
AverageTimeToEmpty() (0x12) Description: Returns predicted remaining battery life (minutes), based AverageCurrent. AverageTimeToEmpty() value calculated based either current power depending setting BatteryMode() CAPACITY_MODE bit. Purpose: AverageTimeToEmpty() function displays state-of-charge information more useful way. averages instantaneous estimations remaining time does appear erratic. SMBus protocol: Read word Output: Unsigned integer-minutes operation left. Units: Minutes Range: 65,534 Granularity: better Accuracy: Invalid Data Indication: 65,535 indicates battery being discharged. AverageTimeToFull() (0x13) Description: Returns predicted remaining time until battery reaches full charge (minutes), based AverageCurrent(). Purpose: AverageTimeToFull() function used SMBus host's power management system policy. also used find long system must left achieve full charge. SMBus protocol: Read word Output: Unsigned integer-remaining time minutes. Units: Minutes Range: 65,534 minutes Granularity: minutes better Accuracy: Invalid Data Indication: 65,535 indicates battery being charged. ChargingCurrent() (0x14) Description: Returns desired charging rate Purpose: ChargingCurrent() function sets maximum charge current battery. ChargingCurrent() value should used combination with ChargingVoltage() value charger's operating point. Together, these functions permit bq2084 dynamically control charging profile (current/voltage) battery. bq2084 effectively turn charger returning value this function. charger operated constant-voltage source above maximum regulated current range returning ChargingCurrent() value 65,535. SMBus protocol: Read word Output: Unsigned integer-maximum charger output current Units: Range: 65,535 Granularity: Accuracy: applicable Invalid Data Indication: 65,535 indicates that charger should operate voltage source outside maximum regulated current range.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ChargingVoltage() (0x15) Description: Returns desired charging voltage Purpose: ChargingVoltage() function sets maximum charge voltage battery. ChargingVoltage() value should used combination with ChargingCurrent() value charger's operating point. Together, these functions permit bq2084 dynamically control charging profile (current/voltage) battery. charger operated constant-current source above maximum regulated voltage range returning ChargingVoltage() value 65,535. SMBus protocol: Read word Output: Unsigned integer-charger output voltage Units: Range: 65,535 Granularity: Accuracy: applicable Invalid Data Indication: 65,535 indicates charger should operate current source outside maximum regulated voltage range. BatteryStatus() (0x16) Description: Returns bq2084 status word (flags). Some BatteryStatus() flags (REMAINING_CAPACITY_ALARM REMAINING_TIME_ALARM) calculated basis either current power depending setting BatteryMode() CAPACITY_MODE bit. This important because wrong calculation mode result inaccurate alarm. Purpose: BatteryStatus() function used power management system alarm status bits, well error codes from bq2084. This basically same information broadcast both SMBus host smart battery charger AlarmWarning() function except that AlarmWarning() function sets error code bits high before sending data. protocol: Read word Output: Unsigned Integer-status register with alarm conditions mapped follows:
ALARM BITS 0x8000 0x4000 0x2000 0x1000 0x0800 0x0400 0x0200 0x0100 STATUS BITS 0x0080 0x0040 0x0020 0x0010 ERROR CODES 0x0007 0x0006 0x0005 0x0004 Unknown Error BadSize Overflow/Underflow AccessDenied Initialized DISCHARGING FULLY_CHARGED FULLY_DISCHARGED OVER_CHARGED_ALARM TERMINATE_CHARGE_ALARM Reserved OVER_TEMP_ALARM TERMINATE_DISCHARGE_ALARM Reserved REMAINING_CAPACITY_ALARM REMAINING_TIME_ALARM
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ERROR CODES 0x0003 0x0002 0x0001 0x0000 UnsupportedCommand ReservedCommand Busy
Alarm Bits OVER_CHARGED_ALARM whenever bq2084 detects that battery being charged beyond maximum overcharge limit, which full capacity plus Maximum Overcharge 0x51-0x52). This cleared when bq2084 detects that battery longer being charged there continuous discharge (i.e., bq2084 detects discharge activity activity above digital filter). TERMINATE_CHARGE_ALARM when bq2084 detects primary charge termination. This cleared when bq2084 detects that battery longer being charged. OVER_TEMP_ALARM when bq2084 detects that internal battery temperature greater than equal OverTemperature Charge threshold while charging OverTemperature Discharge threshold while discharging. This cleared when internal temperature falls back below OverTemperature Charge Reset OverTemperature Discharge Reset appropiate. TERMINATE_DISCHARGE_ALARM when Voltage() Terminate Voltage 0x67-0x68), battery temperature less than equal Charge Suspend Temp 0x79), CVUV pack status set, indicating that Li-Ion cell voltage dropped below limit programmed Cell Under. cleared when Voltage() Terminate Voltage, RM() CVUV cleared. REMAINING_CAPACITY_ALARM when bq2084 detects that RemainingCapacity() less than that RemainingCapacityAlarm() function. This cleared when either value RemainingCapacityAlarm() function lower than RemainingCapacity() when RemainingCapacity() increased charging. REMAINING_TIME_ALARM when bq2084 detects that estimated remaining time present discharge rate less than that RemainingTimeAlarm() function. This cleared when either value RemainingTimeAlarm() function lower than AverageTimeToEmpty() when AverageTimeToEmpty() increased charging. Status Bits initialized when bq2084 detected valid load data flash full partial reset. cleared when bq2084 detects improper data flash load. DISCHARGING when bq2084 determines that battery being charged. This cleared when bq2084 detects that battery being charged. FULLY_CHARGED when bq2084 detects primary charge termination Overcharge condition. cleared when RelativeStateOfCharge() less than programmed Fully Charged Clear 0x4a). FULLY_DISCHARGED when Voltage() VCELL less than EDV2 threshold Current() Overload Current when RelativeStateOfCharge() Battery This cleared when RelativeStateOfCharge() greater than equal 20%.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Error Codes
ERROR CODES Busy Reserved Unsupported AccessDenied Over/Underflow BadSize UnknownError DESCRIPTION bq2084 processed function code without detecting errors. bq2084 unable process function code this time. bq2084 detected attempt read write function code reserved this version specification.The bq2084 detected attempt access unsupported optional manufacturer function code. bq2084 does support this function code which defined this version specification. bq2084 detected attempt write read-only function code. bq2084 detected data overflow underflow. bq2084 detected attempt write function code with incorrect data block. bq2084 detected unidentifiable error.
CycleCount()(0x17) Description: Returns number cycles battery experienced. value each count determined programming Cycle Count Threshold 0x38-0x39) value. bq2084 saves cycle count value Cycle Count 0x0c-0x0d) after update CycleCount(). Purpose: CycleCount() function provides means determine battery wear. used give advance warning that battery nearing life. SMBus protocol: Read word Output: Unsigned integer-count total charge removed from battery over life. Units: cycle Range: 65,534 cycles; 65,535 indicates battery experienced 65,535 more cycles. Granularity: cycle Accuracy: Absolute count DesignCapacity() (0x18) Description: Returns theoretical nominal capacity pack. DesignCapacity() value expressed either current (mAh discharge rate) power, discharge rate) depending setting BatteryMode() CAPACITY_MODE bit. Purpose: DesignCapacity() function used SMBus host's power management conjunction with FullChargeCapacity() determine battery wear. power management system present this information user also adjust power policy result. SMBus protocol: Read word Output: Unsigned integer-battery capacity units mWh.
BATTERY MODES CAPACITY_MODE Units Range Granularity Accuracy 0-65,535 applicable applicable CAPACITY_MODE 0-65,535 applicable applicable
DesignVoltage() (0x19) Description: Returns theoretical voltage pack (mV). bq2084 sets DesignVoltage() value programmed DesignVoltage() 0x04-0x05). Purpose: DesignVoltage() function used give additional information about particular smart battery expected terminal voltage.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
SMBus protocol: Read word Output: Unsigned integer-the battery's designed terminal voltage Units: Range: 65,535 Granularity: applicable Accuracy: applicable SpecificationInfo() (0x1a) Description: Returns version number smart battery specification battery pack supports, well voltage current scaling information packed unsigned integer. Power scaling product voltage scaling times current scaling. SpecificationInfo() packed following fashion: (SpecID_H 0x10 SpecID_L) (VScale IPScale 0x10) 0x100. bq2084 VScale (voltage scaling) IPScale (current scaling) should always zero. bq2084 sets SpecificationInfo() value programmed Specification Information 0x06-0x07). Purpose: SpecificationInfo() function used SMBus host's power management system determine what information smart battery provide. SMBus protocol: Read word Output: Unsigned integer-packed specification number scaling information:
FIELD SpecID_L SpecID_H VScale IPScale BITS USED 8.11 12.15 FORMAT 4-bit binary value 4-bit binary value 4-bit binary value 4-bit binary value 0-15 0-15 (multiplies voltage VScale) (multiplies current IPScale) ALLOWABLE VALUES
ManufactureDate() (0x1b) Description: This function returns date cell pack manufactured packed integer. date packed following fashion: (year-1980) month day. bq2084 sets ManufactureDate() value programmed Manufacture Date 0x08-0x09). Purpose: ManufactureDate() provides system with information that used uniquely identify particular battery pack when used conjunction with SerialNumber(). SMBus protocol: Read word Output: Unsigned integer-packed date manufacture:
FIELD Month Year BITS USED 9.15 FORMAT 5-bit binary value 4-bit binary value 7-bit binary value ALLOWABLE VALUES 0-31 (corresponds date) 1-12 (corresponds month number) 0-127 (corresponds year biased 1980)
SerialNumber() (0x1c) Description: This function used return serial number. This number, when combined with ManufacturerName(), DeviceName(), ManufactureDate(), uniquely identifies battery (unsigned integer). bq2084 sets SerialNumber() value programmed Serial Number 0x0a-0x0b). Purpose: SerialNumber() function used identify particular battery. This important systems that powered multiple batteries where system information about each battery that encounters. SMBus protocol: Read word Output: Unsigned integer
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ManufacturerName() (0x20) Description: This function returns character array containing battery manufacturer's name. example, MyBattCo identifies smart battery manufacturer MyBattCo. bq2084 sets ManufacturerName() value programmed Manufacturer Name 0x0e-0x19. Purpose: ManufacturerName() function returns name smart battery manufacturer. manufacturer's name displayed SMBus host's power management system display both identifier advertisement manufacturer. name also useful part information required uniquely identify battery. SMBus protocol: Read block Output: String-character string with maximum length characters length byte). DeviceName() (0x21) Description: This function returns character string that contains battery name. example, DeviceName() bq2084 indicates that battery model bq2084. bq2084 sets DeviceName() value programmed Device Name 0x1a-0x21). Purpose: DeviceName() function returns battery name identification purposes. SMBus protocol: Read block Output: String-character string with maximum length characters length byte). DeviceChemistry() (0x22) Description: This function returns character string that contains battery chemistry. example, DeviceChemistry() function returns NiMH, battery pack contains nickel metal hydride cells. bq2084 sets DeviceChemistry() value programmed Device Chemistry 0x22-0x26). Purpose: DeviceChemistry() function gives cell chemistry information charging systems. bq2084 does DeviceChemisty() values internal charge control fuel gauging. SMBus protocol: Read block Output: String-character string with maximum length characters length byte). following partial list chemistries their expected abbreviations. These abbreviations case sensitive.
CHEMISTRY Lead acid Lithium Nickel cadmium Nickel metal hydride Nickel zinc Rechargeable alkaline-manganese Zinc ABBREVIATIONS PbAc LION NiCd NiMH NiZn ZnAr
ManufacturerData() (0x23) Description: This function allows access manufacturer data contained battery (data). bq2084 stores seven critical operating parameters this data area. Purpose: ManufacturerData() function used access manufacturer's data area. data fields this command reflect programming eight critical data flash locations used facilitate evaluation bq2084 under various programming sets. ManufacturerData() function returns following information order: Pack Configuration, Gauge Configuration, Misc Configuration bytes), Digital Filter, Self Discharge Rate, Pack Load Estimate, Battery Low%, Near Full bytes) Status, pending threshold voltage (low byte high byte). SMBus protocol: Read block
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Output: Block data-data that reflects data flash programming assigned manufacturer with maximum length characters length byte). Pack Status Pack Configuration (0x2f) This function returns pack status pack configuration registers. pack status register contains number status bits relating bq2084 operation. pack status register least significant byte word. pack configuration register reflects bq2084 configured defined value programmed Pack Configuration 0x28). pack status register consists following bits:
PRES EDV2 AFEFAIL CVOV CVUV
PRES PRES indicates that bq2084 been inserted into system. EDV2 EDV2 indicates that pack cell voltage (program option) less than EDV2 threshold. indicates seal state bq2084. AFEFAIL AFEFAIL indicates that commuunications failed. indicates present discharge cycle valid update. indicates that bq2084 Flag been set. cleared only when Flag been cleared CVOV CVOV indicates that protection limit been exceeded including Prolonged Overcurrent, Overvoltage, Overtemperature conditions. latched merely reflects present fault status. secondary protection limits exceeded secondary protection limit exceeded bq2084 Flag 0x00 bq2084 Flag 0x66 Discharge cycle valid Discharge cycle valid communications okay communications have failed bq2084 unsealed state bq2084 sealed state Voltage EDV2 threshold (discharging) Voltage EDV2 threshold bq2084 system bq2084 inserted into system
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
CVUV CVUV indicates that protection limit been exceeded including overload overdischarge conditions. latched merely reflects present fault status. secondary protection limits exceeded secondary protection limit exceeded
VCELL4-VCELL1 (0x3c-0x3f) These functions return calculated individual cell voltages
General
bq2084 accesses internal data flash during reset when storing historical data. data flash stores basic configuration information bq2084. data flash must programmed correctly proper bq2084 operation.
Memory
following table shows memory data flash. shows default programming bq2084. default programming reflects example data 3s2p Li-Ion battery pack with 0.02- sense resistor. data flash must reprogrammed meet requirements individual applications.
DATA FLASH ADDRESS HIGH BYTE 0x00 0x02 0x04 0x06 0x08 0x0a 0x0c 0x0e 0x0f 0x10 0x11 0x12 0x13 0x14 0x15 0x16 0x17 0x18 0x19 0x1a 0x1b 0x1c 0x1d 0x1e 0x1f 0x20 0x21 BYTE 0x01 0x03 0x05 0x07 0x09 0x0b 0x0d NAME Remaining Time Alarm Remaining Capacity Alarm Design Voltage Specification Information Manufacture Date Serial Number Cycle Count Manufacturer Name Length Character Character Character Character Character Character Character Character Character Character Character Device Name Length Character Character Character Character Character Character Character LI-ION EXAMPLE minutes 14400 v1.1/PEC 1/1/2003 11809 DATA
Reserved locations must shown. Locations marked with typical calibration values that adjusted maximum accuracy. these locations table shows appropriate default initial setting.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
DATA FLASH ADDRESS HIGH BYTE 0x22 0x23 0x24 0x25 0x26 0x27 0x28 0x29 0x2a 0x2c 0x2d 0x2e 0x2f 0x30 0x32 0x34 0x36 0x38 0x3a 0x3c 0x3e 0x40 0x42 0x44 0x45 0x46 0x47 0x49 0x4a 0x4b 0x4d 0x4f 0x50 0x51 0x53 0x54 0x55 0x56 0x58 0x59 0x5b 0x5d 0x5f 0x61 0x63 0x65 0x67 0x5a 0x5c 0x5e 0x60 0x62 0x64 0x66 0x68 0x57 0x52 0x4c 0x4e 0x48 0x31 0x33 0x35 0x37 0x39 0x3b 0x3d 0x3f 0x41 0x43 0x2b BYTE
NAME Device Chemistry Length Character Character Character Character Manufacturer Data Length Pack Configuration Gauge Configuration Misc Configuration Digital Filter (Dead Band) Self-Discharge Rate Electronics Load Battery Near Full Design Capacity Reserved Full Charge Capacity Cycle Count Threshold Charging Voltage Precharge Voltage Fast-Charging Current Maintenance Charging Current Precharge Current Precharge Temperature Precharge Temperature Hysteresis Charge Inhibit Temp Charge Inhibit Temp High Fast Charge Termination Fully Charged Clear Current Taper Threshold Current Taper Qual Voltage Current Taper Window Reserved Maximum Overcharge Reserved Charge Efficiency Reserved Reserved Reserved Reserved Overload Current Over Voltage Margin Reserved Clear Fail Current Cell Over Voltage Cell Under Voltage Terminate Voltage
LI-ION EXAMPLE DMODE, 4-LEDs, 4-CELL CSYNC, OTVC 9860 0.2% 7.03% 7200 7200 5200 16800 2500 2500 9.6°C 3.0°C 0.0°C 50.0°C 100% 100%
DATA
5000 4350 2300 11300
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
DATA FLASH ADDRESS HIGH BYTE 0x69 0x6b 0x6d 0x6f 0x71 0x73 0x75 0x77 0x79 0x7a 0x7b 0x7c 0x7e 0x80 0x81 0x82 0x83 0x85 0x86 0x87 0x88 0x8a 0x8b 0x8c 0x8d 0x8e 0x8f 0x90 0x92 0x94 0x95 0x97 0x99 0x9b 0x9d 0x9f 0xa0 0xa1 0xa2 0xa3 0xa4 0xa5 0xa6 0xa8 0xaa 0xab 0xac 0xa7 0xa9 0x96 0x98 0x9a 0x9c 0x9e 0x91 0x93 0x89 0x84 0x7d 0x7f BYTE 0x6a 0x6c 0x6e 0x70 0x72 0x74 0x76 0x78
NAME Reserved Safety Over Voltage Charge Suspend Temp High Charge Suspend Temp High Reset Over Temperature Discharge Over Temperature Discharge Reset Safety OverTemperature Charge Safety OverTemperature Discharge Charge Suspend Temp Reserved Current Deadband Shutdown Voltage VOC75 Reserved Reserved Reserved VOC50 Reserved Reserved Reserved VOC25 Reserved Reserved Reserved Reserved Voltage Average Time Correction Current Limit Reserved Reserved Reserved EMF/EDV0 Factor/EDV1 Factor/EDV2 Factor Factor Factor Factor Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Learning Temp
LI-ION EXAMPLE
DATA
20000 60°C 55°C 70°C 60°C 75°C 75°C 8800 15848
15240
15024
3000 3250 3400
11.9°C
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
DATA FLASH ADDRESS HIGH BYTE 0xad 0xae 0xb0 0xb2 0xb3 0xb4 0xb5 0xb7 0xb9 0xbb 0xbd 0xbf 0xc1 0xc2 0xc3 0xc4 0xc5 0xc6 0xc7 0xc8 0xc9 0xcb 0xcd 0xcf 0xd1 0xd2 0xd4 0xd5 0xd6 0xd7 0xd8 0xda 0xdc 0xdd 0xdf 0xe0 0xe2 0xe4 0xe6 0xe8 0xea 0xec 0xed 0xee 0xf0 0xf2 0xf4 0xef 0xf1 0xf3 0xf5 0xe1 0xe3 0xe5 0xe7 0xe9 0xeb 0xde 0xd9 0xdb 0xd3 0xca 0xcc 0xce 0xd0 0xb6 0xb8 0xba 0xcc 0xce 0xc0 0xaf 0xb1 BYTE
NAME Reserved Reserved Reserved Reserved Reserved Reserved Const Const Const Const Const Reserved Reserved State Control Function Control Cell Select Overload Overload Delay Short Circuit Charge Short Circuit Discharge Vref* Sense Resistor Gain* Delta* Delta* Reserved Offset* Offset* Offset* Temperature Offset* Board Offset* Reserved Reserved Reserved Version Reserved Cell Over Voltage Reset Cell Under Voltage Reset Fail Limit Reserved Cell Balance Thresh Cell Balance Window Cell Balance Cell Balance Interval Cell Imbalance Threshold Balance Vcell Balance Imax Reserved
LI-ION EXAMPLE
DATA
9750 0.02 0.0000323
49701
4150 3000 counts 3900
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
DATA FLASH ADDRESS HIGH BYTE 0xf6 0xf8 0xfa 0xfb 0xfc 0xfd 0xfe 0xff 0x101 0x103 0x105 0x107 0x109 0x10b 0x10d 0x10f 0x111 0x113 0x115 0x117 0x119 0x11b 0x11d 0x11e 0x11f 0x120 0x121 0x123 0x125 0x127 0x129 0x12a 0x12c 0x12d 0x12f 0x130 0x131 0x133 0x132 0x12e 0x12b 0x122 0x124 0x126 0x128 0x100 0x102 0x104 0x106 0x108 0x10a 0x10c 0x10e 0x110 0x112 0x114 0x116 0x118 0x11a 0x11c BYTE 0xf7 0xf9
NAME Reserved Reserved Reserved Check Time Sleep Current Thresh Sleep Current Multiplier Sleep Time Manufacturer Info Manufacturer Info Manufacturer Info Vmax Charge Voltage Voff Charge Voltage Charge Voltage Pulse Time Pulse Time Charge Time Precharge Detection Current Charge Detection Current Discharge Detection Current Reserved Reserved Reserved Permanent Fail Status Permanent Fail Flag Permanent Fail Config Permanent Fail Input Time Reserved Reserved Fail Charge Current Fail Discharge Current Fail Time Charge Threshold Charge Time Discharge Threshold Discharge Time Fault Reset Time VPACK Threshold Shutdown Timer
LI-ION EXAMPLE
DATA
counts
4280 4280 4200 0.125 7200 -150
4000 10970
ADDITIONAL PROGRAMMING INFORMATION Additional Data Flash Programming
following sections describe function each data flash location data stored.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
ADDITIONAL PROGRAMMING INFORMATION (continued)
Sense Resistor Value 32-bit Delta 0xcd-0xd0) corrects coulomb counter sense resistor variations. represents gain factor coulomb counter. 16-bit Sense Resistor Gain 0xcb-0xcc) scales each integrating converter conversion mAh. Current() related measurement Sense Resistor Gain based resistance series sense resistor. following formula computes nominal starting value Sense Resistor Gain from sense resistor value Sense Resistor Gain 306.25
RSNS VALUE SENSE RESISTOR GAIN 61250 30625 15312
offset offset 0xd2-0xd3), contains offset coulomb counter. automatically updated when pack conditions sleep, before enters sleep mode. offset offset 0xd4), contains offset pack ground reference. automatically updated when pack conditions sleep, before enters sleep mode. offset offset 0xd5), contains offset converter. automatically updated when pack conditions sleep, before enters sleep mode. Digital Filter desired digital filter threshold, (V), value stored Digital Filter 0x2c). Digital Filter Battery Pack Capacity Voltage Pack capacity units stored Design Capacity 0x32-0x33). mode, bq2084 copies Design Capacity DesignCapacity(). mode, bq2084 multiplies Design Capacity Design Voltage 0x04-0x05) calculate DesignCapacity() scaled mWh. Design Voltage stored initial value Full Charge Capacity, mAh, stored 0x36-0x37. Full Charge Capacity modified over course pack usage reflect cell aging under particular conditions. bq2084 updates Full Charge Capacity after capacity learning cycle. Remaining Time Capacity Alarms Remaining Time Alarm 0x00-0x01) Remaining Capacity Alarm 0x02-0x03) alarm thresholds used SMBus command codes 0x01 0x02, respectively. Remaining Time Alarm stored minutes Remaining Capacity Alarm units mWh, depending BatteryMode() setting. Cycle Count Initialization Cycle Count 0x0c-0x0d) stores initial value CycleCount() function. should programmed 0x0000. Cycle Count Threshold Cycle Count Threshold 0x37-0x38) sets number that must removed from battery increment CycleCount(). Cycle Count threshold 16-bit value stored mAh.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Charge Efficiency bq2084 applies efficiency factor, EFF%, charge added battery. EFF% encoded Charge Efficiency 0x54) according equation Charge Efficiency (EFF% 2.56
Pack Options
Pack Configuration Pack Configuration 0x28) contains bit-programmable features.
DMODE LED1 LED0
DMODE DMODE determines whether outputs indicate AbsoluteStateOfCharge() RelativeStateOfCharge(). LEDs reflect AbsoluteStateOfCharge() LEDs reflect RelativeStateOfCharge()
LED1-LED0 bits number LEDs Remaining Capacity indication. enables/disables transmissions smart battery host master mode alarm messages. enables/disables transmissions smart battery charger master mode messages. enables/disables master mode broadcasts bq2084. CC1-CC0 bits configure bq2084 number series cells battery pack. Configures bq2084 four series cells Configures bq2084 three series cells Configures bq2084 series cells Broadcasts host charger enabled Broadcasts host charger disabled byte broadcasts charger byte broadcasts charger byte alarm warning host byte alarm warning host Configures bq2084 five LEDs Configures bq2084 three LEDs Configures bq2084 four LEDs Configures bq2084 five LEDs
set, modifications bits BatteryMode() re-enable broadcasts.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Gauge Configuration Gauge Configuration 0x29) contains bit-programmable features:
CSYNC CEDV EDVV OVSEL VCOR OTVC
CSYNC usual operation bq2084, CSYNC that coulomb counter adjusted when fast charge termination detected. some applications, especially those where externally controlled charger used, desirable adjust coulomb counter. these cases CSYNC should cleared. enables learning cycle optimization Smart Charger independent charge. CEDV CEDV determines whether bq2084 implements automatic compensation calculate EDV0, EDV1, EDV2 thresholds base rate, temperature, capacity. cleared, bq2084 uses fixed values programmed data flash EDV0, EDV1, EDV2. set, bq2084 calculates EDV0, EDV1, EDV2. EDVV EDVV selects whether termination done with regard Voltage lowest single-cell voltage. OVSEL OVSEL determines Safety Over Voltage based Voltage highest cell voltages. VCOR VCOR enables midrange voltage correction algorithm. When set, bq2084 compares pack voltage adjust according values programmed VOC25, VOC50, VOC75. OTVC OTVC programs bq2084 perform midrange voltage time after device reset One-time midrange correction disabled One-time midrange correction enabled Continuous midrange corrections disabled Continuous midrange corrections enabled Safety overvoltage based Voltage Safety overvoltage based highest cell voltage multiplied number cells then compared safety voltage. conditions determined basis lowest single-cell voltage conditions determined basis Voltage() compensation disabled compensation enabled Learning cycle optimized independent charger Learning cycle optimized Smart Charger bq2084 does alter time valid charge termination. bq2084 updates with programmed percentage valid charger termination.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Miscellaneous Configuration Misc Configuration 0x2a-0x2b, high-low) contains additional bit-programmable features. Misc Configuration 0x2a high)
AFEDET ECLED
configures bq2084 internal temperature sensor. constants 0xb5-0xc0 need match required thermistor internal temperature sensor. Data Flash Settings Internal External Temperature Sensor Table. AFEDET AFEDET programs bq2084 look errors with communications enables detection permanent failure Config 0x11f set. programs bq2084 enter sleep mode SMBus inactivity. programs bq2084 turn discharge when bq2084 detects overtemperature condition. Charge always turned overtemperature conditions. ECLED ECLED programs activity during charging (DSG enables time delay setting CVOV CVUV bits PackStatus. delay delay LEDs enabled during charging. LEDs enabled during charging. bq2084 does turn discharge overtemperature. bq2084 turns discharge overtemperature. bq2084 enters sleep mode when SMBus bq2084 does enter sleep mode. Does verify communications. Does verify communications. bq2084 requires external thermistor. bq2084 uses internal temperature sensor.
Misc Configuration 0x2b low)
LEDRCA PFET1 PFET0 CHGFET
LEDRCA LEDRCA programs blink when there RemainingCapacityAlarm. LEDs blink when there RemainingCapacityAlarm. LEDs there RemainingCapacityAlarm.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
PFET1, PFET0 PFETx bits define precharge operation. bq29312 data sheet more detail. defines whether bq2084 used with nonremovable system battery. indicate nonremovable system battery there additional clear conditions battery failure overcharge, overcurrent, overload. additional conditions besides battery removal (defined loss system present going high) either detection opposite current that that caused failure when AverageCurrent() less than Clear Fail Current 0x61, 0x62) time defined Fault Reset Time 0x130). Also, nonremovable battery, charge left discharge current failures discharge left charge current failures. CHGFET CHGFET programs charge remain even after charge terminate condition. charge turned after charge termination condition. charge turned after charge termination condition. Removable battery, battery fail conditions cleared battery removal only. Nonremovable system battery. bq29312 ZVCHG turned precharge. Assumes charger precharge function. charge turned precharge. Assumes charger precharge function. bq29312 turned precharge. Assumes charger does have precharge function. defined, unpredictable operation
Constants String Data
Specification Information Specification Information 0x06-0x07) stores default value SpecificationInfo() function. stored data flash same format data returned SpecificationInfo(). Manufacture Date Manufacture Date 0x08-0x09) stores default value ManufactureDate() function. stored data flash same format data returned ManufactureDate(). Serial Number Serial Number 0x0a-0x0b) stores default value SerialNumber() function. stored data flash same format data returned SerialNumber(). Manufacturer Name Length Manufacturer Name Length 0x0e) stores length desired string that returned ManufacturerName() function. Locations 0x0f-0x19 store characters ManufacturerName() ASCII code. Device Name Length Device Name Length 0x1a) stores length desired string that returned DeviceName() function. Locations 0x1b-0x21 store characters DeviceName() ASCII code. Device Chemistry Length Device Chemistry Length 0x22) stores length desired string that returned DeviceChemistry() function. Locations 0x23-0x26 store characters DeviceChemistry() ASCII code.
bq2084
SLUS550E DECEMBER 2002 REVISED JUNE 2005
Manufacturers Data Length Manufacturers Data Length 0x27) stores length desired number bytes that returned ManufacturersData() function. should
Temperature Limits
limits described below extensions those limits detailed safety charging sections this data sheet. Charge Suspend Temp Charge Suspend Temp 0x79) sets lowest temperature, degrees which normal operation allowed. temperature falls below this limit, pack goes into temporary failure state, charge turned off, status system present. cleared when pack warms, pack removed. Charge Inhibit Temp Charge Inhibit Temp 0x46) inhibits charging setting ChargingCurrent() ChargingVoltage() turn FET. programmed degrees range -12.8°C 12.7°C. Charge Inhibit Temp High Charge Inhibit Temp High 0x47-0x48) inhibits charging setting ChargingCurrent() ChargingVoltage() Charge Suspend Temp High Charge Suspend Temp High 0x6d-0x6e) sets highest temperature, degrees ÷ which charging will allowed continue. this temperature exceeded during charging, pack goes into temporary failure state, status system present. cleared when pack cools below Charge Suspend Temp High Reset adapter removed, pack removed. Charging only resume when temperature returns within charge start temperature limits. Charge Suspend Temp High Reset Charge Suspend Temp High Reset 0x6f-0x70) sets temperature, degrees ÷ which pack recovers from Charge Suspend Temp High fault. Over Temperature Discharge Over Temperature Discharge 0x71-0x72) sets highest temperature, degrees ÷ which discharging will allowed. pack exceeds this temperature, charge discharge FETs turned off, status system-present. pack returns normal operation when temperature falls below Over Temperature Discharge Reset, pack removed. Over Temperature Discharge Reset Over Temperature Discharge Reset 0x73-0x74) sets temperature, degrees ÷ which pack recovers from Over Temperature Discharge.
Failure Detection Thresholds
Safety OverTemperature Charge Safety OverTemperature Charge 0x75-0x76) sets temperature, degrees ÷ above which, during charging, pack enters permanent failure, XSOTC Permanent Failure Configuration set. Safety OverTemperature Disch
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