Remote Thermal Diode Monitor with Linear Control ADM1028 ADM1028

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Remote Thermal Diode Monitor with Linear Control ADM1028 ADM1028

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FEATURES On-Chip Temperature Sensor External Temperature Measurement with Remote Diode Interrupt Over-Temperature Outputs Fault-Tolerant Control with Auto Hardware Trip Point Remote Reset Power-Down Functions LDCM Support System Management (SMBus) Communications Standby Mode Minimize Power Consumption Limit Comparison Monitored Values APPLICATIONS Network Servers Personal Computers Microprocessor-Based Office Equipment Test Equipment Measuring Instruments
Remote Thermal Diode Monitor with Linear Control ADM1028
ADM1028 low-cost temperature monitor controller microprocessor-based systems. temperature remote sensor diode measured, allowing monitoring processor temperature single processor systems. on-chip temperature sensor monitors ambient system temperature. Measured values read System Management Bus, values limit comparisons programmed over same serial bus. ADM1028 also contains speed control. automatic hardware temperature trip point provided will driven full speed exceeded. Finally, chip remote reset power-down functionality, allowing remotely shut down SMBus. ADM1028's supply voltage range, supply current, SMBus make ideal wide range applications. These include hardware monitoring applications PCs, electronic test equipment, office electronics.
FUNCTIONAL BLOCK DIAGRAM
VCC3AUX
VCC3AUX R_OFF R_RST
ADM1028
POWER-ON RESET SERIAL INTERFACE REMOTE FUNCTION REGISTER ANALOG OUTPUT REGISTER 8-BIT VALUE LIMIT REGISTERS LIMIT COMPARATORS
AUXRST
RESET FAN_SPD SHUTOFF R_OFF RESET
ADDRESS POINTER REGISTER
FAN_SPD/NTEST_IN
ALERT STATUS REGISTER
ANALOG SIGNAL CONDITIONING VCC3AUX THERMA/NTEST_OUT
INTERRUPT STATUS REGISTERS MASK REGISTER MASK GATING
2.5V BANDGAP REFERENCE
THERMB
CONFIGURATION REGISTER
FAN_OFF
REV.
Information furnished Analog Devices believed accurate reliable. However, responsibility assumed Analog Devices use, infringements patents other rights third parties which result from use. license granted implication otherwise under patent patent rights Analog Devices. Technology Way, P.O. 9106, Norwood, 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Site: http://www.analog.com Fax: 781/326-8703 Analog Devices, Inc., 2000
ADM1028-SPECIFICATIONS1,
TMAX, VMIN VMAX, unless otherwise noted.)
Unit Test Conditions
Parameter POWER SUPPLY Supply Voltage, Supply Current, TEMPERATURE-TO-DIGITAL CONVERTER Internal Sensor Accuracy Resolution External Diode Sensor Accuracy Resolution Remote Sensor Source Current ANALOG OUTPUT Output Voltage Range Total Unadjusted Error, Full-Scale Error Zero Error Differential Nonlinearity, Integral Nonlinearity Output Source Current Output Sink Current THERMA OUTPUT THERMA Pull-Up Resistance DIGITAL OUTPUT THERMA/NTEST_OUT, R_OFF Output High Voltage, Output Voltage, OPEN-DRAIN DIGITAL OUTPUTS (INT, THERMB, FAN_OFF, R_RST) Output Voltage, High Level Output Leakage Current, OPEN-DRAIN SERIAL DATA OUTPUT (SDA) Output Voltage, High Level Output Leakage Current, SERIAL DIGITAL INPUTS (SCL, SDA) Input High Voltage, Input Voltage, Input Leakage Current Hysteresis DIGITAL INPUT LOGIC LEVELS (FAN_SPD/TEST_IN, GPI) Input High Voltage, Input Voltage, DIGITAL INPUT LEAKAGE CURRENT (ALL DIGITAL INPUTS) Input High Current, Input Current, Input Capacitance,
3.30
Interface Inactive, Active Inactive
60°C 100°C 60°C 100°C High Level 0.65 Level 0.65
Load Monotonic Design
IOUT
IOUT -3.0 VOUT VCC3
IOUT -3.0 VOUT
Note
-0.005 0.005
Note
REV.
ADM1028
Parameter SERIAL TIMING4 Clock Frequency, fSCLK Free Time, tBUF Start Setup Time, tSU;STA Start Hold Time, tHD;STA Stop Condition Setup Time, tSU;STO Time, tLOW High Time, tHIGH SCL, Rise Time, SCL, Fall Time, Data Setup Time, tSU;DAT Data Hold Time, tHD;DAT 1000 Unit Test Conditions Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure
NOTES Typicals 25°C represent most likely parametric norm. Standby current measured with Timing specifications tested logic levels falling edge rising edge. FAN_OFF guaranteed design, production tested. Guaranteed design, production tested. Specifications subject change without notice.
ABSOLUTE MAXIMUM RATINGS*
Positive Supply Voltage (VCC) Voltage Digital Inputs Except Therm -0.3 +6.5 Voltage Therm -0.3 Voltage -0.3 Voltage Other Input -0.3 Output Input Current Package Input Current Maximum Junction Temperature max) 150°C Storage Temperature Range -65°C +150°C Lead Temperature Soldering sec) 300°C Reflow Peak Temperature 220°C Rating (Human Body Model) 4000
*Stresses above those listed under Absolute Maximum Ratings cause permanent damage device. This stress rating only; functional. Operation device these other conditions above those indicated operational section this specification implied. Exposure absolute maximum rating conditions extended periods affect device reliability.
THERMAL CHARACTERISTICS
16-Lead QSOP Package: 105°C/W, 39°C/W
ORDERING GUIDE Model Temperature Range Package Description Package Option
ADM1028ARQ 100°C
Shrink Small Outline RQ-16 Package (QSOP)
tHD;STA tLOW
tHD;STA
tHD;DAT
tHIGH
tSU;DAT
tSU;STA
tSU;STO
tBUF
Figure Diagram Serial Timing
REV.
ADM1028
FUNCTION DESCRIPTIONS
Mnemonic FAN_OFF
Description Digital Output (Open Drain) Request. When asserted low, this indicates request shut independent FAN_SPD output. When negated (output off) indicates that turned Digital Input tolerant). This general-purpose logic input with tolerance. programmed active high active input that sets Interrupt Status Register. voltage >2.2 this pin, represents Logic "1," while floating condition interpreted Logic "0." Digital Input. This driven input reset ADM1028. Ground. Power signal ground. Power Aux. Power source voltage monitor input power-on reset. Digital Input. This pulled externally indicate ADM1028 that main system power been removed. ADM1028 will shut FAN_SPD output reset R_OFF output. Digital Output (Open Drain). This remote reset output that pulses receipt specific SMBus message. Analog Output/Test Input. active-high input that enables NAND board-level connectivity testing. Refer section NAND testing. Used analog output speed control when NAND test selected. Remote Thermal Diode Negative Input. This negative input (current sink) from remote thermal diode. This also serves negative input into A/D. Remote Thermal Diode Positive Input. This positive input (current source) from remote thermal diode. This serves positive input into A/D. Digital Output (Open Drain with Integrated VCC3AUX Pull-Up). active thermal overload output that indicates violation temperature setpoint (over temperature). full-speed whenever this asserted low. Acts output NAND Tree when ADM1028 NAND Tree Test Mode. Digital Output (Open Drain). This second THERM signal. used drive external circuitry with different external pull-up supply rail. Digital Output Open Drain with Integrated VCC3AUX Pull-Up. Remote (powerdown) output. This driven high receipt specific SMBus message. (and associated register bit) remain high until input asserted low. Digital Output (Open Drain), System Interrupt Output. This signal indicates violation trip point. output enabled when Configuration Register default state disabled. Digital Input. SMBus Clock. Digital (Open Drain). SMBus Bidirectional Data.
AUXRST VCC3AUX
R_RST FAN_SPD/NTEST_IN
THERMA/NTEST_OUT
THERMB R_OFF
CONFIGURATION
FAN_OFF AUXRST
R_OFF VIEW VCC3AUX (Not Scale) THERMB
ADM1028
R_RST FAN_SPD/NTEST_IN
THERMA/NTEST_OUT
REV.
Typical Performance Characteristics-ADM1028
TEMPERATURE ERROR
LOWER SPEC LEVEL
ERROR
UPPER SPEC LEVEL
LEAKAGE RESISTANCE
TEMPERATURE
Temperature Error Board Track Resistance VDD)
Temperature Error ADM1028 Pentium® Temperature
250mV
TEMPERATURE ERROR
TEMPERATURE ERROR
100mV
100k FREQUENCY
100M 1000M
CAPACITANCE
Temperature Error Power Supply Noise Frequency
Temperature Error Capacitance Between
TEMPERATURE ERROR
2.02
100mV
1.97
SUPPLY CURRENT
100k FREQUENCY 100M 25mV 50mV
1.92 1.87 1.82 1.77 1.72 3.3V 1.67 SCLK FREQUENCY 1000
Temperature Error Common-Mode Noise Frequency
Standby Current Clock Frequency
REV.
ADM1028
10mV
TEMPERATURE ERROR
3.0V 3.3V 5.5V
STANDBY SUPPLY CURRENT
100k FREQUENCY
100M
TEMPERATURE
Temperature Error Differential-Mode Noise Frequency
Standby Supply Current Temperature
FUNCTIONAL DESCRIPTION
SERIAL INTERFACE
ADM1028 low-cost temperature monitor controller microprocessor-based systems. temperature remote sensor diode measured, allowing monitoring processor temperature single-processor system. onchip temperature sensor allows monitoring system ambient temperature. Measured values read serial System Management Bus, values limit comparisons programmed over same serial bus. ADM1028 also contains speed control. automatic hardware temperature trip point provided fault tolerant control will driven full speed this exceeded. interrupt outputs provided, which will asserted software hardware limits exceeded. Finally, chip remote reset shutdown capabilities.
INTERNAL REGISTERS ADM1028
Control ADM1028 carried serial bus. ADM1028 connected this slave device, under control master device, e.g. chipset. ADM1028 7-bit serial address. When device powers will with default serial address. SMBus address ADM1028 0101110 binary. serial protocol operates follows: master initiates data transfer establishing START condition, defined high-to-low transition serial data line SDA, while serial clock line remains high. This indicates that address/data stream will follow. slave peripherals connected serial respond START condition, shift next eight bits, consisting 7-bit address (MSB first) plus bit, which determines direction data transfer, i.e., whether data will written read from slave device. peripheral whose address corresponds transmitted address responds pulling data line during period before ninth clock pulse, known Acknowledge Bit. other devices remain idle while selected device waits data read from written master will write slave device. master will read from slave device. Data sent over serial sequences nine clock pulses, eight bits data followed Acknowledge from slave device. Transitions data line must occur during period clock signal remain stable during high period, low-to-high transition when clock high interpreted STOP signal. number data bytes that transmitted over serial single READ WRITE operation limited only what master slave devices handle. When data bytes have been read written, stop conditions established. WRITE mode, master will pull data line high during tenth clock pulse assert STOP condition. READ mode, master device will override acknowledge pulling data line high during period before ninth clock pulse. This known Acknowledge. master will then take REV.
brief description ADM1028's principal internal registers given below. More detailed information function each register given Tables Configuration Register: Provides control configuration. Address Pointer Register: This register contains address that selects other internal registers. When writing ADM1028, first byte data always register address, which written Address Pointer Register. Interrupt (INT) Status Register: This register provides status each Interrupt event. Interrupt (INT) Mask Register: Allows masking individual interrupt sources. Value Limit Registers: results temperature measurements stored these registers, along with their limit values. Analog Output Register: code controlling analog output stored this register. Alert Status Register: Indicates status THERM signal pin. Remote Function Register: This register allows control R_RST R_OFF outputs.
ADM1028
data line during period before tenth clock pulse, then high during tenth clock pulse assert STOP condition. number bytes data transferred over serial operation, possible read write operation, because type operation determined beginning cannot subsequently changed without starting operation. case ADM1028, write operations contain either bytes, read operations contain byte, perform following functions: write data device data registers read data from Address Pointer Register must that correct data register addressed, then data written into that register read from first byte write operation always contains address that stored Address Pointer Register. data written device, write operation contains second data byte that written register selected address pointer register.
This illustrated Figure device address sent over followed This followed data bytes. first data byte address internal data register written which stored Address Pointer Register. second data byte data written internal data register. When reading data from register there only possibility: serial address written device along with address pointer register value. ADM1028 should then acknowledge write pulling during ninth clock pulse. master does generate STOP condition issues START condition. serial address again sent with high, indicating READ operation. ADM1028 will then return data from selected register, Acknowledge generated signify read operation. master will then initiate STOP condition transaction release SMBus. Figures serial address shown default value 0101110.
START MASTER
ACK. ADM1028
ACK. ADM1028
FRAME SERIAL ADDRESS BYTE (CONTINUED)
FRAME ADDRESS POINTER REGISTER BYTE
(CONTINUED)
ACK. ADM1028 STOP MASTER
FRAME DATA BYTE
Figure Writing Register Address Address Pointer Register, then Writing Data Selected Register
START MASTER
ACK. ADM1028
ACK. ADM1028
FRAME SERIAL ADDRESS BYTE
FRAME ADDRESS POINTER REGISTER BYTE
START MASTER
ACK. ADM1028
ACK. MASTER STOP MASTER
FRAME SERIAL ADDRESS BYTE
FRAME DATA BYTE FROM ADM1028
Figure Reading Data from ADM1028
REV.
ADM1028
TEMPERATURE MEASUREMENT SYSTEM Internal Temperature Measurement Table Temperature Data Format
ADM1028 contains on-chip bandgap temperature sensor. on-chip performs conversions output this sensor outputs temperature data 8-bit two's complement format. format temperature data shown Table
External Temperature Measurement
Temperature -128°C -125°C -100°C -75°C -50°C -25°C -1°C +1°C +10°C +25°C +50°C +75°C +100°C +125°C +127°C
Digital Output 1000 0000 1000 0011 1001 1100 1011 0101 1100 1110 1110 0111 1111 1111 0000 0000 0000 0001 0000 1010 0001 1001 0011 0010 0100 1011 0110 0100 0111 1101 0111 1111
ADM1028 measure temperature external diode sensor diode-connected transistor, connected Pins Pins dedicated temperature input channel. default functions Pins THERM outputs indicate over-temperature conditions. forward voltage diode diode-connected transistor, operated constant current, exhibits negative temperature coefficient about mV/°C. Unfortunately, absolute value varies from device device, individual calibration required null this out, making technique unsuitable mass production. technique used ADM1028 measure change when device operated different currents. This given KT/q ln(N) where: Boltzmann's constant. charge carrier. absolute temperature Kelvins. ratio currents. Figure shows input signal conditioning used measure output external temperature sensor. This figure shows external sensor substrate transistor, provided temperature monitoring some microprocessors, could equally well discrete transistor.
IBIAS
measure VBE, sensor switched between operating currents resulting waveform passed through low-pass filter remove noise, thence chopper-stabilized amplifier that performs functions amplification rectification waveform produce voltage proportional VBE. This voltage measured give temperature output 8-bit two's complement format. further reduce effects noise, digital filtering performed averaging results measurement cycles. external temperature measurement nominally takes
LAYOUT CONSIDERATIONS
Digital boards electrically noisy environments, care must taken protect analog inputs from noise, particularly when measuring very small voltages from remote diode sensor. following precautions should taken: Place ADM1028 close possible remote sensing diode. Provided that worst noise sources such clock generators, data/address buses CRTs avoided, this distance inches. Route tracks close together, parallel with grounded guard tracks each side. Provide ground plane under tracks possible. wide tracks minimize inductance reduce noise pickup. track minimum width spacing recommended. minimize number copper/solder joints, which cause thermocouple effects. Where copper/solder joints used, make sure that they both path same temperature. Thermocouple effects should major problem corresponds about thermocouple voltages about µV/oC temperature difference. Unless there thermocouples with temperature differential between them, thermocouple voltages should much less than Place bypass 2200 input filter capacitors close ADM1028. distance remote sensor more than inches, twisted-pair cable recommended. This will work about feet. REV.
REMOTE SENSING TRANSISTOR
VOUT+
BIAS DIODE
VOUT- LOW-PASS FILTER 65kHz
Figure Signal Conditioning
discrete transistor used, collector will grounded, should linked base. transistor used, base connected input emitter input. transistor used, emitter connected input base input. prevent ground noise interfering with measurement, more negative terminal sensor referenced ground, biased above ground internal diode input. sensor used very noisy environment, capacitor value 1000 placed between inputs filter noise.
ADM1028
really long distances feet) shielded twistedpair such Belden #8451 microphone cable. Connect twisted pair shield close ADM1028. Leave remote shield unconnected avoid ground loops.
10MIL 10MIL 10MIL 10MIL 10MIL
FAN_SPD AD8519
FAN_SPD AD8541
NDT452
Figure Circuit with
BD136 2SA968
10MIL 10MIL
Figure Arrangement Signal Tracks
Because measurement technique uses switched current sources, excessive cable and/or filter capacitance affect measurement. When using long cables, filter capacitor reduced removed. case, total shunt capacitance should exceed 1000 Cable resistance also introduce errors. series resistance introduces about 0.5°C error.
ANALOG OUTPUT
Figure Circuit with Transistor
100k FAN_SPD AD8519
3.3V
NDT452
ADM1028 single analog output (FAN_SPD) from unsigned 8-bit which produces analog output register defaults during power-on reset, which produces minimum speed. analog output amplified buffered with external circuitry such transistor provide speed control. Suitable drive circuits given Figures When using these circuits, following points should noted: these circuits will provide output range from zero almost +VFAN. amplify range analog output +VFAN, gain these circuits needs shown. Care must taken when choosing ensure that input common-mode range output voltage swing suitable. powered from rail alone. powered from then input common-mode range should include ground accommodate minimum output voltage DAC, output voltage should swing below ensure that transistor turned fully off. these circuits, output transistor must have ICMAX greater than maximum current, capable dissipating power voltage dropped across when operating full-speed. motor produces large back e.m.f. when switched off, necessary clamp diodes protect output transistors event that output very quickly goes from full-scale zero. Figure shows FAN_OFF signal used (with control circuits) gate independent value FAN_SPD/NTEST_IN pin. REV.
FAN_OFF
MMFT305
Figure Circuit with P-Channel MOSFET
100k
100k
NDT452
FAN_SPD
Q1/Q2 MBT3904 DUAL
3.9k
Figure Discrete Drive Circuit with P-Channel MOSFET, Single Supply
BD132 TIP32A
100k
100k
BC556 2N3906
FAN_SPD
Q1/Q2 MBT3904 DUAL
3.9k
Figure Discrete Drive Circuit with Bipolar Output Single Supply
ADM1028
FAULT TOLERANT CONTROL
TEMP HIGH LIMIT
ADM1028 incorporates fault tolerant control capability that tied operation THERMA, THERMB outputs. override setting analog output force maximum give full speed event critical overtemperature problem, even some reason, this been handled system software. There temperature point registers that will activate fault tolerant control. these limits programmable user hardware (read-only) register that will operate user does program limit. fault tolerant control activated limit exceeded three more consecutive readings. These limits separate from normal high temperature limits output, which affect fault tolerant control THERM outputs. hardware limit 100°C programmed into register address 18h, remote diode Default THERM limit. This default limit analog output will forced fullscale remote sensor reads more than 100°C. This makes fault tolerant control fail-safe that will operate this temperature even user programmed other limit, event software malfunction. Similarly, Default Internal Temp THERM limit held register 17h, forces analog output full-scale ambient temperature measured more than 70°C. user override default limits programming limit into register remote sensor limit into register internal sensor. default value register same read-only register (100°C), programmed with higher lower values. Once registers have been programmed, defaults acceptable, configuration register must "1." This write-once that only written "1," effects: makes values registers active limits, disables read-only registers 18h. locks data into registers 14h, that cannot changed until lock reset, either when AUXRST asserted, Power-On Reset occurs. Once hardware override analog output triggered, will only return normal operation after three consecutive measurements that degrees lower than limit. Whenever FAN_SPD output forced full-scale, FAN_OFF output negated.
ADM1028 INTERRUPT SYSTEM
LIMIT
*INT CLEARED SOFTWARE
THIGH INTERRUPT LOGIC REARMED HERE
Figure Operation Output
Once interrupt been cleared, will reasserted even temperature remains outside limit previously exceeded. However, will rearmed temperature falls back within limits three consecutive conversions. Once function been rearmed, will then reasserted once limit exceeded three consecutive conversions.
INTERRUPT MASKING
bits Interrupt Status Register masked setting corresponding mask Interrupt Mask Register. That interrupt source will then longer generate interrupt. However, bits status register will normal.
INTERRUPT CLEARING
Interrupt Status Register reflects out-of-limit conditions. Status bits individually cleared writing appropriate status bits. Writing Bits causes software interrupts generated. (GPI) Interrupt Status Register reflects current status pin, cannot cleared writing this bit. output cleared with INT_Enable bit, which Configuration Register, without affecting contents Interrupt (INT) Status Registers.
THERM OUTPUTS
THERMA, THERMB signals functionally identical. These system over-temperature outputs will assert together when over-temperature detected. THERMA (Pin open drain digital output which integrated pull-up resistor VCC3AUX. THERMB open drain digital output, intended drive external circuitry operating different supply voltage level.
THERM OPERATING MODE
ADM1028 three interrupt outputs, INT, THERMA THERMB. These have different functions. responds violations software programmed temperature limits interrupt sources maskable, described more detail later. Interrupts status bits only limit exceeded least three consecutive conversions. Operation output illustrated Figure Assuming that temperature starts within programmed limits that temperature interrupt sources masked, will temperature measured external sensor goes outside programmed high temperature limit sensor. also goes whenever THERM low. -10-
THERM only responds "hardware" temperature limits addresses 18h, software programmed limits. function these registers described earlier with regard fault tolerant speed control. THERM will hardware temperature limit exceeded three consecutive measurements. will remain until temperature falls degrees below limit three consecutive measurements. While THERM low, analog output will boost controlled full speed FAN_OFF will negated.
REV.
ADM1028
GENERAL-PURPOSE LOGIC INPUT (GPI)
HARDWARE TRIP POINT TEMP
THERM PROGRAMMED VALUE PREVIOUS SPEED VALUE
ANALOG OUTPUT
used general-purpose logic input with tolerance. input programmed active high active clearing setting Configuration Register. default value active high. Interrupt Status register follows state inverted state) will generate interrupt when like other input Interrupt Status Register. However, latched Status Register always reflects current state inverted state) input. will cleared reading Status Register.
POWER-ON RESET
Figure Operation THERM Outputs
When Fault Tolerant Control state exited, analog FAN_SPD output returns previously programmed value, which have been changed during time that FAN_SPD output forced FFh.
INTERRUPT STRUCTURE
Interrupt Structure ADM1028 shown more detail Figure each measurement value obtained stored appropriate value register, value limits from corresponding limit registers high limit comparators. result each comparison limit, limit) routed corresponding input Interrupt Status Register data demultiplexer, used that high appropriate. Interrupt Mask Register bits corresponding each Interrupt Status Register Bits. Setting Interrupt Mask high forces corresponding Status output low, while setting Interrupt Mask allows corresponding Status asserted. After masking, status bits OR'd together produce output, which will pull unmasked status goes high, i.e. when measured value goes limit. output enabled when Configuration Register (INT_Enable) high.
When ADM1028 powered will initiate power-on reset sequence when supply voltage VCC3AUX rises above power-on reset threshold, with registers being reset their power-on values. Normal operation will begin when supply voltage rises above reset threshold. Registers whose poweron values shown have power-on conditions that indeterminate (this includes Value Limit Registers). most applications, usually first action after power-on would write limits into Limit Registers. Power-on reset clears initializes following registers (the initialized values shown Table III): Configuration Register Interrupt Status Register Interrupt Mask Register Analog Output Register Programmable Trip Point Registers
ADM1028 also reset taking AUXRST input. registers will reset their default values will remain inactive long AUXRST below reset threshold. Taking will cause following registers reset. Configuration Register (Programmable THERM Limit Lock Bit) Output, Speed
INT. TEMP HIGH LIMIT FROM VALUE VALUE LIMIT REGISTERS LIMIT HIGH LIMIT COMPARATORS FLAG1 DATA LIMIT DEMULTIPLEXER FLAG2 INT. THERM EXT. TEMP EXT. THERM DIODE FAULT
INTERRUPT STATUS REGISTER MASK GATING STATUS MASK INTERRUPT MASK REGISTER INT_ENABLE
MASKING DATA FROM EIGHT MASK BITS (SAME ORDER STATUS REGISTER)
CONFIGURATION REGISTER
Figure Interrupt Register Structure
REV.
-11-
ADM1028
INITIALIZATION (SOFT RESET)
Soft reset performs similar, identical, function power-on reset. restores power-on default values Configuration Register, Interrupt Status Register Interrupt Mask Register. Limit Registers remain unchanged. rearms structure THERM structure. Soft reset accomplished setting Configuration Register high. This automatically clears after being set. Unlike clearing INT, where temperature must fall back within limits three conversions before function rearmed, soft reset allows pulled immediately after soft reset.
NAND TREE TEST
output tree, cycling toward farthest, causes output tree toggle with each input change. Allow typical propagation delay
POWER-ON RESET FAN_SPD/ NTEST_IN LATCH ENABLE AUXRST
THERMA/ NTEST_OUT
NAND tree provided ADM1028 Automated Test Equipment (ATE) board level connectivity testing. device placed into NAND tree test mode powering with FAN_SPD/NTEST_IN (Pin held high. This sampled state power-up latched. connected high, then NAND tree test mode invoked. NAND tree test mode will only exited once ADM1028 powered down. NAND tree test mode, digital inputs tested illustrated Table THERMA/NTEST_OUT will become NAND tree output pin. structure NAND Tree shown Figure perform NAND Tree test, pins initially driven low. test vectors inputs then, one-by-one, toggles them high (keeping them high). Exercising test circuit with this "walking one" pattern, starting with input closest
Figure NAND Tree
CONFIGURING INTERRUPT
power-up, Interrupt functionality device disabled. Configuration Register (0x40) must written order enable interrupt output. INT_Enable (Bit Register should
Table Test Vectors
AUXRST
THERMA
-12-
REV.
ADM1028
Table III. ADM1028 Registers
Register Name Value Registers Company Revision
Address A7-A0 0x14-0x38 0x3E 0x3F
Comments Table This location will contain company identification number. This register read only. This location will contain revision number part lower four bits register [3:0]. upper four bits reflect ADM1028 Version Number [7:4]. first version 1101. next version ADM1028 would 1110, etc. instance, stepping were this part ADM1028, this register would read 1101 0000. This register read only. Table Power-on value 0010 0001. Table Power-on value 0000 0000. Table VII. Power-on value 0000 0000. Test Registers manufacturer's only. write these registers. Table VIII. Power-on value 0000 0000. Table Power-on value 0000 0000.
Configuration Register Interrupt Status Register Interrupt Mask Register Manufacturer Test Remote Function Alert Status
0x40 0x41 0x43 0x44-0x4A 0x4B 0x4C
Table Registers 0x13-0x3A Value Registers
Address 0x13 0x14
Read/Write Read/Write Read/Write
Description Programmable Internal Therm Automatic Trip Point-Default 127°C. This register only written write once Configuration Register (0x40, been set. Programmable Remote Thermal Diode Automatic Trip Point-Default 100°C. This register only written write once Configuration Register (0x40, been set. Test register manufacturer's only. write this register. Default Internal Therm Automatic Trip Point-Default 70°C. Cannot changed. Disabled when Configuration Register set. Default Remote Thermal Diode Automatic Trip Point-Default 100°C. Cannot changed. Disabled when Configuration Register set. Analog Output, FAN_SPD (Defaults 0x00h). External/Remote Temperature Value. Internal Temperature Value. External/Remote Temperature High Limit-Default +127°C. External/Remote Temperature Limit-Default -128°C. Internal Temperature High Limit-Default +127°C. Internal Temperature Limit-Default -128°C.
0x15 0x17 0x18 0x19 0x26 0x27 0x37 0x38 0x39 0x3A
Read/Write Read Only Read Only Read/Write Read Only Read Only Read/Write Read/Write Read/Write Read/Write
REV.
-13-
ADM1028
Table Register 0x40 Configuration Register Power-On Default <7:0>
Name START
Read/Write
Description Setting this enables startup ADM1028; clearing this places ADM1028 standby mode. startup, temperature monitoring limit checking functions begin. Note, limit values should programmed into ADM1028 prior using standard thermal interrupt mechanism based upon high limits. (Power-Up Default Setting this enables output. Enabled Disabled (Power-Up Default Reserved (Default Setting this will lock value into Programmable Remote Therm Limit Register (Value Register 0x14). Furthermore, this set, values Default Remote Therm Limit Register (Value Register 0x18) will longer have effect THERM, FAN_SPD, FAN_OFF outputs. This cannot bewritten again until after been asserted. (Power-Up Default Setting this will restore power-up default values Configuration Register, Interrupt Status Register Interrupt Mask Register. This also rearms structure THERM structure. This automatically clears itself since power-on default zero. Setting this will cause FAN_OFF floated. Clearing this will cause FAN_OFF driven which requests that turned off. This will unconditionally THERM ever asserted; once THERM negated this must returned prior state (prior THERM assertion). Reading this reflects state FAN_OFF output buffer. open-drain nature this value read does represent actual state external circuit connected (Power-Up Default =1.) Setting this will invert input purpose level detection interrupt generation. Clearing this leaves input unmodified. (Power-Up Default Reserved. (Power-Up Default
Enable Reserved Programmable Therm Limit Lock
Read/Write Read Only Read/Write Once
Soft Reset
Read/Write
FAN_OFF
Read/Write
Invert
Read/Write
Reserved
Read Only
-14-
REV.
ADM1028
Table Register 0x41. Interrupt Status Register. Power-On Default <7:0>
Name Int. Temp Error Flag
Read/Write Read/Write clear Read/Write
Description indicates that limits internal temperature sensor been exceeded. This used general purpose flag with capability generating interrupt. Writing this causes "1." Writing clears this bit. This used general purpose flag with capability generating interrupt. Writing this causes "1." Writing clears this bit. indicates that internal thermal overload (THERM) limit been exceeded. indicates that asserted. polarity determined Invert (Bit Configuration Register. example, Invert cleared then this will when high ("1"); this will when ("0".) Invert then this will when ("0"); this will when high ("1"). Note that state latched; this simply reflects state inverted state pin. Note: this reading this register will clear "0." indicates that limits external temperature sensor been exceeded. indicates that external thermal overload (THERM) limit been exceeded. indicates either short- open-circuit fault remote sensor diode.
Flag
Read/Write
Int. THERM Input
Read/Write clear Read Only
Ext. Temp Error Ext. THERM Diode Fault
Read/Write clear Read/Write clear Read/Write clear
Table VII. Register 0x43 Interrupt Mask Register. Power-On Default <7:0>
Name Temp Error Flag Mask Flag Mask THERM Mask Temp Error THERM Diode Fault
Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write
Description disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output. disables corresponding interrupt status output.
REV.
-15-
ADM1028
Table VIII. Register 0x4B Remote Function Register. Power-On Default <7:0>
Name R_RST
Read/Write Read/Write
Description Writing this causes R_RST output pulsed minimum This will self-clear when R_RST pulse complete. Writing this effect. Reading this reflects state this register state pin. power-on default value "0." Writing this causes R_OFF output driven high. This will cleared, output driven low, when asserted. Writing this effect. power-on default value "0." Reserved (Default Reserved (Default Reserved (Default Reserved (Default Reserved (Default Reserved (Default
R_OFF
Read/Write
Reserved Reserved Reserved Reserved Reserved Reserved
Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write
Table Register 0x4C Alert Status Register. Power-On Default <7:0>
Name THERM Alert Alert
Read/Write Read Only Read Only
Description indicates that external thermal overload limit currently exceeded. This represents logic level Configuration Register "0," inverse logic level Configuration Register "1." indicates that internal thermal overload limit currently exceeded. Undefined. Undefined. Undefined. Undefined. Undefined.
THERM Alert Reserved Reserved Reserved Reserved Reserved
Read Only Read Only Read Only Read Only Read Only Read Only
OUTLINE DIMENSIONS
Dimensions shown inches (mm).
Shrink Small Outline Package (QSOP) (RQ-16)
0.197 (5.00) 0.189 (4.80)
0.157 (3.99) 0.150 (3.81)
0.244 (6.20) 0.228 (5.79)
0.059 (1.50)
0.069 (1.75) 0.053 (1.35)
0.010 (0.25) 0.004 (0.10)
0.025 (0.64)
0.012 (0.30) SEATING 0.010 (0.20) 0.008 (0.20) PLANE 0.007 (0.18)
0.050 (1.27) 0.016 (0.41)
REF: JEDEC 0.150" SSOP DRAWING NUMBER MO-137
-16-
REV.
PRINTED U.S.A.
C01632-2.5-10/00 (rev.

Remote Thermal Diode Monitor with Linear Control ADM1028 ADM1028

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