Adaptive Step-Up Converters with 1.5A Flash Driver 2.5V 5.5V Oper
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19-4421; 4/09
Adaptive Step-Up Converters with 1.5A Flash Driver
2.5V 5.5V Operation Range Step-Up DC-DC Converter 1.5A Guaranteed Output Current Adaptive Programmable Output Voltage 2MHz 4MHz Switching Frequency Options Flash/Movie Current Regulators Programmable Flash Movie Current Low-Dropout Voltage (110mV max) 500mA Indicator Current Regulator Programmable Output Current Ramp Blink Timers Indicator Mode Low-Dropout Voltage (130mV max) 16mA Programmable Safety Watchdog Timers Blank Logic Input MAXFLASH System Lockup Protection Remote Temperature Sensor Input Open/Short Detection Thermal Shutdown Protection Shutdown Current 20-Bump, 0.5mm Pitch, 2.5mm 2.0mm
MAX8834Y/MAX8834Z
MAX8834Y/MAX8834Z flash drivers integrate 1.5A DC-DC step-up converter three programmable low-side, low-dropout current regulators. step-up converter features internal switching MOSFET synchronous rectifier improve efficiency minimize external component count. interface provides flexible control stepup converter output voltage setting, movie/flash mode selection, flash timer duration settings, current regulator settings. MAX8834Y/MAX8834Z operate down 2.5V, making them future proof battery technologies. MAX8834Y/MAX8834Z consist current regulators flash/movie mode. Each current regulator sink 750mA flash mode 125mA movie mode. MAX8834Y/MAX8834Z also integrate 16mA lowcurrent regulator that used indicate camera status. indicator current regulator includes programmable ramp blink timer settings. programmable input current limit, invoked using GSMB control, reduces total current drawn from battery during transmit events. This ensures flash current maximum possible given operating condition. Additionally, MAX8834Y/MAX8834Z include MAXFLASH* function that adaptively reduces flash current during battery conditions help prevent system undervoltage lockup. Other features include optional input fingerburn protection open/short detection. MAX8834Y switches 2MHz, providing best overall efficiency. MAX8834Z switches 4MHz, providing smallest overall solution size. MAX8834Y/ MAX8834Z available 20-bump, 0.5mm pitch package (2.5mm 2.0mm).
*Patent pending.
Applications
Cell Phones Smart Phones PDAs, Digital Cameras, Camcorders
Typical Operating Circuit
2.2H PROGRAMMABLE OUTPUT 3.7V 5.2V AGND
INPUT 2.5V 5.5V
Ordering Information
PART SWITCHING TEMP PIN-PACKAGE FREQUENCY RANGE (MHz)
PA_TXON FLASH VLOGIC 0.1F
PGND COMP FLED1 1.5A TOTAL FLASH FLED2
MAX8834Y MAX8834Z
-40°C MAX8834YEWP+T +85°C (2.5mm 2.0mm) MAX8834ZEWP+T -40°C +85°C (2.5mm 2.0mm)
GSMB LED_EN
INDLED 16mA INDICATOR FGND FINGER-BURN PROTECTION
+Denotes lead(Pb)-free/RoHS-compliant package. Tape reel.
Configuration appears data sheet.
Maxim Integrated Products
pricing, delivery, ordering information, please contact Maxim Direct 1-888-629-4642, visit Maxim's website www.maxim-ic.com.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
ABSOLUTE MAXIMUM RATINGS
OUT, AGND .-0.3V +6.0V AGND.-0.3V +4.0V SCL, SDA, LED_EN, GSMB AGND .-0.3V (VDD 0.3V) FLED1, FLED2, INDLED FGND .-0.3V (VOUT 0.3V) COMP AGND .-0.3V (VIN 0.3V) PGND, FGND AGND .-0.3V +0.3V Current (rms) Continuous Power Dissipation +70°C) (derate 17.5mW/°C above +70°C) .1410mW Operating Temperature Range .-40°C +85°C Junction Temperature .+150°C Storage Temperature Range .-65°C +150°C Bump Temperature* (soldering) .+260°C
*This device constructed using unique packaging techniques that impose limit thermal profile device exposed during board level solder attach rework. This limit permits only solder profiles recommended industry-standard specification, JEDEC 020A, paragraph 7.6, Table IR/VPR Convection reflow. Preheating required. Hand wave soldering allowed.
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 operational sections specifications implied. Exposure absolute maximum rating conditions extended periods affect device reliability.
ELECTRICAL CHARACTERISTICS
(VIN 3.6V, VAGND VPGND VFGND 1.8V, -40°C +85°C, unless otherwise noted. Typical values +25°C.) (Note
PARAMETER Operating Voltage Operating Range Undervoltage Lockout (UVLO) Threshold UVLO Hysteresis UVLO Threshold UVLO Hysteresis Standby Supply Current Standby Supply Current (All Outputs Off, Enabled) LOGIC INTERFACE LED_EN, GSMB Logic Input-High Voltage 1.62V 3.6V SCL, LED_EN, GSMB Logic Input-Low Voltage 1.62V 3.6V SCL, From LED_EN going high rising edge current regulator 3.6V +25°C +85°C VSCL VSDA VDD, 5.5V, ready VSCL VSDA 3.6V, ready falling 2.15 falling CONDITIONS 1.62 1.25 2.45 1.55 UNITS
LED_EN Minimum High Time (LED_EN Internally Sampled 1MHz Clock) LED_EN Propagation Delay LED_EN GSMB Pulldown Resistor Logic Input Current (SCL, SDA)
0.01 1600
Adaptive Step-Up Converters with 1.5A Flash Driver
ELECTRICAL CHARACTERISTICS (continued)
(VIN 3.6V, VAGND VPGND VFGND 1.8V, -40°C +85°C, unless otherwise noted. Typical values +25°C.) (Note
PARAMETER Shutdown Leakage Current INTERFACE Output Voltage Clock Frequency Bus-Free Time Between STOP START Hold Time Repeated START Condition Period High Period Setup Time Repeated START Condition Hold Time Setup Time Setup Time STOP Condition STEP-UP DC-DC CONVERTER Voltage Range Voltage Accuracy Overvoltage Protection Adaptive Output Voltage Regulation Threshold PGOOD Window Comparator Line Regulation Load Regulation nFET Current Limit nFET On-Resistance pFET On-Resistance Leakage Input Current Limit Range During GSMB Trigger Input Current Limit Step Size During GSMB Trigger Input Current Limit Accuracy ILIM 100mA, dropout mode MAX8834Y Operating Frequency, Load MAX8834Z +25°C -40°C +85°C +25°C -40°C +85°C PGND, 200mA OUT, 200mA 5.5V +25°C +85°C 100mV steps load, VOUT When running adaptive mode IFLED1 IFLED2 492.24mA setting, IINDLED 16mA VOUT programmable mode 2.5V 4.2V 1500mA -2.75 ±0.5 5.35 -12.5 0.055 0.12 0.130 0.200 +2.75 tBUF tHD_STA tLOW tHIGH SU_STA tHD_DAT SU_DAT SU_STO -0.01 0.03 CONDITIONS UVLO, VLED_EN VGSMB +25°C +85°C 0.01 UNITS
MAX8834Y/MAX8834Z
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
ELECTRICAL CHARACTERISTICS (continued)
(VIN 3.6V, VAGND VPGND VFGND 1.8V, -40°C +85°C, unless otherwise noted. Typical values +25°C.) (Note
PARAMETER Maximum Duty Cycle Minimum Duty Cycle COMP Transconductance COMP Discharge Resistance Discharge Resistance VOUT 4.5V VOUT 4.5V VCOMP 1.5V During shutdown UVLO, from COMP AGND During shutdown UVLO, from Step-up off, FLED1/FLED2 supply current each current source Flash Movie 23.44mA setting Current Accuracy 492.24mA setting 750mA setting Current Regulator Dropout (Note FLED1/FLED2 Leakage Shutdown 492.24mA setting 93.75mA setting VFLED1 VFLED2 5.5V +25°C +85°C 0.01 0.5mA setting Current Accuracy Current Regulator Dropout INDLED Leakage Shutdown PROTECTION CIRCUITS BIAS Current Overtemperature Detection Threshold Short Detection Threshold Flash Duration Timer Range Flash Duration Timer Accuracy (400ms Setting) Minimum Flash Duration Flash Safety Timer Reset Inhibit Period Watchdog Timer Range VNTC falling, 100mV hysteresis, NTC_CNTL[2:0] VNTC falling 50ms steps (Note +25°C -40°C +85°C FLASH_EN[2:0] From falling edge LED_EN until flash safety timer reset steps 19.4 20.6 16mA setting 16mA setting (Note VINDLED 5.5V +25°C +85°C +25°C +25°C -40°C +85°C 0.01 ±0.5 +25°C +25°C -40°C +85°C -40°C +85°C -2.5 ±0.5 CONDITIONS UNITS
FLED1/FLED2 CURRENT REGULATOR Supply Current Maximum Current Setting +2.5
INDLED CURRENT REGULATOR Supply Current Step-up converter off, INDLED Maximum Current Setting
Adaptive Step-Up Converters with 1.5A Flash Driver
ELECTRICAL CHARACTERISTICS (continued)
(VIN 3.6V, VAGND VPGND VFGND 1.8V, -40°C +85°C, unless otherwise noted. Typical values +25°C.) (Note
PARAMETER Watchdog Timer Accuracy setting) Open Detection Threshold +25°C -40°C +85°C FLED1, FLED2, INDLED enabled VOUT +160 CONDITIONS UNITS
MAX8834Y/MAX8834Z
Shorted Detection Threshold FLED1, FLED2, INDLED enabled Open Short Debounce Timer Thermal-Shutdown Hysteresis Thermal Shutdown MAXFLASH Low-Battery Detect Threshold Range Low-Battery Voltage Threshold Accuracy Low-Battery Voltage Hysteresis Programmable Range Low-Battery Voltage Hysteresis Step Size Low-Battery Reset Time LB_TMR[1:0] LB_TMR[1:0] 33mV steps From open short detected until current regulator disabled
±2.5
Note devices 100% production tested +25°C. Limits over operating temperature range guaranteed design. Note current regulator dropout voltage defined voltage when current drops from current level measured 0.6V. Note Flash duration from rising edge LED_EN until IFLED (safety time one-shot mode). Note adaptive output voltage regulation threshold individually each device 75mV above dropout voltage current regulators. This ensures minimum power dissipation during flash event. dropout voltage chosen highest measured dropout voltage FLED1, FLED2, INDLED.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Typical Operating Characteristics
(Circuit Figure 3.6V, VOUT 3.8V, 3.0V, +25°C, unless otherwise noted.)
STEP-UP CONVERTER EFFICIENCY INPUT VOLTAGE (MAX8834Y)
MAX8834Y/Z toc01
STEP-UP CONVERTER EFFICIENCY INPUT VOLTAGE (MAX8834Z)
MAX8834Y/Z toc02
STEP-UP CONVERTER EFFICIENCY OUTPUT CURRENT (MAX8834Y)
3.6V 3.2V 2.5V
MAX8834Y/Z toc03
EFFICIENCY VOUT 3.8V IOUT 750mA VOUT IOUT 250mA VOUT 3.8V IOUT 250mA VOUT IOUT 16mA VOUT 3.8V IOUT 16mA
EFFICIENCY VOUT IOUT 250mA VOUT 3.8V IOUT 250mA VOUT VOUT 3.8V IOUT 16mA IOUT 16mA VOUT 3.8V IOUT 750mA VOUT IOUT 750mA
EFFICIENCY
VOUT IOUT 750mA
VOUT, VOUT INCREASES ABOVE PROGRAMMED VALUE MINIMUM DUTY CYCLE CONSTRAINT.
VOUT, VOUT INCREASES ABOVE PROGRAMMED VALUE MINIMUM DUTY CYCLE CONSTRAINT.
1000 10,000 OUTPUT CURRENT (mA)
INPUT VOLTAGE
INPUT VOLTAGE
STEP-UP CONVERTER EFFICIENCY OUTPUT CURRENT (MAX8834Z)
MAX8834Y/Z toc04
STEP-UP CONVERTER SUPPLY CURRENT SUPPLY VOLTAGE
VOUT 3.8V SUPPLY CURRENT (mA) MAX8834Z
MAX8834Y/Z toc05
STEP-UP CONVERTER SUPPLY CURRENT TEMPERATURE
VOUT SUPPLY CURRENT (mA) MAX8834Z
MAX8834Y/Z toc06
3.6V 3.2V 2.5V
EFFICIENCY
MAX8834Y
MAX8834Y
SUPPLY VOLTAGE TEMPERATURE (°C)
1000 10,000 OUTPUT CURRENT (mA)
CURRENT ACCURACY INPUT VOLTAGE
MAX8834Y/Z toc07
CURRENT ACCURACY TEMPERATURE
CURRENT ACCURACY IFLED2 492.19mA VOUT IFLED2 750mA IINDLED 16mA IFLED1 750mA IFLED1 125mA
MAX8834Y/Z toc08
CURRENT ACCURACY IFLED1 125mA IFLED1 492.19mA IFLED2 492.19mA IFLED1 750mA IFLED2 750mA VOUT INPUT VOLTAGE IINDLED 16mA IFLED2 125mA
IFLED2 125mA IFLED1 492.19mA
TEMPERATURE (°C)
Adaptive Step-Up Converters with 1.5A Flash Driver
Typical Operating Characteristics (continued)
(Circuit Figure 3.6V, VOUT 3.8V, 3.0V, +25°C, unless otherwise noted.)
OUTPUT VOLTAGE ACCURACY TEMPERATURE
MAX8834Y/Z toc09
MAX8834Y/MAX8834Z
INTERNAL OSCILLATOR FREQUENCY SUPPLY VOLTAGE
MAX8834Y/Z toc10
OUTPUT VOLTAGE ACCURACY MAX8834Z, LOAD -0.2 -0.4 -0.6 MAX8834Z, IOUT 250mA
VOUT MAX8834Y, LOAD
OSCILLATOR FREQUENCY (MHz) MAX8834Z
MAX8834Y, IOUT 250mA
MAX8834Y
TEMPERATURE (°C) SUPPLY VOLTAGE
STARTUP WAVEFORM (MAX8834Y, VOUT
MAX8834Y/Z toc11
STARTUP WAVEFORM (MAX8834Y, ADAPTIVE MODE)
MAX8834Y/Z toc12
VOUT
2V/div
VOUT
2V/div
2V/div
ADAPTIVE MODE ILED1 31.25mA
2V/div
VOUT ILED1 31.25mA 500mA/div
500mA/div
VCOMP 1ms/div
1V/div
VCOMP 1ms/div
1V/div
STARTUP WAVEFORM (MAX8834Z, VOUT
MAX8834Y/Z toc13
STARTUP WAVEFORM (MAX8834Z, ADAPTIVE MODE)
MAX8834Y/Z toc14
VOUT
2V/div
VOUT
2V/div
VOUT ILED1 31.25mA
2V/div
2V/div
500mA/div 1V/div VCOMP 1ms/div
ADAPTIVE MODE ILED1 31.25mA
500mA/div
VCOMP 1ms/div
1V/div
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Typical Operating Characteristics (continued)
(Circuit Figure 3.6V, VOUT 3.8V, 3.0V, +25°C, unless otherwise noted.)
SHUTDOWN WAVEFORM (MAX8834Y, VOUT
MAX8834Y/Z toc15
SHUTDOWN WAVEFORM (MAX8834Y, ADAPTIVE MODE)
MAX8834Y/Z toc16
VOUT
2V/div
VOUT
2V/div
2V/div
2V/div
VOUT ILED1 31.25mA VCOMP 400s/div
500mA/div 1V/div
ADAPTIVE MODE ILED1 31.25mA
500mA/div
VCOMP 400s/div
1V/div
SHUTDOWN WAVEFORM (MAX8834Z, VOUT
MAX8834Y/Z toc17
SHUTDOWN WAVEFORM (MAX8834Z, ADAPTIVE MODE)
MAX8834Y/Z toc18
VOUT
2V/div
VOUT
2V/div
2V/div
2V/div
VCOMP
VOUT ILED1 31.25mA
500mA/div
ADAPTIVE MODE ILED1 31.25mA
500mA/div
1V/div
VCOMP 1V/div
400s/div
400s/div
LIGHT-LOAD SWITCHING WAVEFORMS (MAX8834Y)
MAX8834Y/Z toc19
LIGHT-LOAD SWITCHING WAVEFORMS (MAX8834Z)
MAX8834Y/Z toc20
2V/div
2V/div
VOUT IOUT 16mA
200mA/div
VOUT IOUT 16mA
200mA/div
VOUT RIPPLE 400ns/div
20mV/div
VOUT RIPPLE 400ns/div
20mV/div
Adaptive Step-Up Converters with 1.5A Flash Driver
Typical Operating Characteristics (continued)
(Circuit Figure 3.6V, VOUT 3.8V, 3.0V, +25°C, unless otherwise noted.)
HEAVY-LOAD SWITCHING WAVEFORMS (MAX8834Y)
MAX8834Y/Z toc21
MAX8834Y/MAX8834Z
HEAVY-LOAD SWITCHING WAVEFORMS (MAX8834Z)
MAX8834Y/Z toc22
2V/div
2V/div 500mA/div 1.5A VOUT IOUT
VOUT IOUT VOUT RIPPLE 400ns/div
1.5A 500mA/div
50mV/div
VOUT RIPPLE 400ns/div
50mV/div
GSMB WAVEFORM
MAX8834Y/Z toc23
MAXFLASH FUNCTION
MAX8834Y/Z toc24
VGSMB
VOUT ILIM 500mA IFLED1 IFLED2 515.63mA tHC_TRM
2V/div 1A/div
3.6V
DROPS BELOW THRESHOLD VOLTAGE
3.6V 200mV/div
INCREASES THRESHOLD IFLED1 500mA/div IFLED1 IFLED2 1ms/div 500mA/div VOUT IFLED1 750mA VLB_TH 3.0V VLB_HYS DISABLED tTMR_DUR 50ms 10ms/div
200mV/div
OUTPUT VOLTAGE LINE REGULATION (MAX8834Y)
MAX8834Y/Z toc25
OUTPUT VOLTAGE LINE REGULATION (MAX8834Z)
VOUT 5.01 OUTPUT VOLTAGE IOUT 16mA
MAX8834Y/Z toc26
5.02 VOUT 5.01 OUTPUT VOLTAGE IOUT 16mA 5.00
5.02
5.00
4.99 IOUT 250mA IOUT 750mA 4.98
4.99
IOUT 250mA
IOUT 750mA
4.98
4.97 INPUT VOLTAGE
4.97 INPUT VOLTAGE
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Typical Operating Characteristics (continued)
(Circuit Figure 3.6V, VOUT 3.8V, 3.0V, +25°C, unless otherwise noted.)
OUTPUT VOLTAGE LOAD REGULATION (MAX8834Y)
MAX8834Y/Z toc27
OUTPUT VOLTAGE LOAD REGULATION (MAX8834Z)
MAX8834Y/Z toc28
5.02 5.01 OUTPUT VOLTAGE 5.00 4.99 4.98 4.97 VOUT 4.96 1000
5.02 5.01 OUTPUT VOLTAGE 5.00 4.99 4.98 4.97 VOUT 4.96
10,000
1000
10,000
OUTPUT CURRENT (mA)
OUTPUT CURRENT (mA)
INPUT CURRENT LIMIT PROGRAMMED OUTPUT VOLTAGE
ILIM 500mA
MAX8834Y/Z toc29
INPUT CURRENT LIMIT PROGRAMMED VALUE
VOUT INPUT CURRENT LIMIT (mA)
MAX8834Y/Z toc30
INPUT CURRENT LIMIT (mA)
1000
IDEAL LINE
PROGRAMMED OUTPUT VOLTAGE PROGRAMMED VALUE (mA)
Adaptive Step-Up Converters with 1.5A Flash Driver
Description
NAME FUNCTION Regulator Output. Connect anodes external LEDs. Bypass PGND with ceramic capacitor. connected through internal resistor during shutdown. Inductor Connection. Connect switched side inductor. internally connected drains internal MOSFETs. connected through internal resistor during shutdown. Power Ground. Connect PGND AGND input capacitor ground. Connect PGND ground plane. Analog Supply Voltage Input. input voltage range 2.5V 5.5V. Bypass AGND PGND with ceramic capacitor close possible high impedance during shutdown. Logic Input Supply Voltage. Connect logic supply driving SCL, SDA, LED_EN, GSMB. Bypass AGND with 0.1F ceramic capacitor. When below UVLO, registers reset step-up converter turns off. Clock Input. Data read rising edge SCL. Analog Ground. Connect AGND PGND input capacitor ground. Connect AGND ground plane. Compensation Input. Compensation Network Selection section details. COMP internally pulled AGND through resistor shutdown. FLED1/FLED2 INDLED Power Ground. Connect FGND PGND. Enable Logic Input. LED_EN controls FLED1, FLED2, INDLED, depending control bits written into LED_CNTL register. LED_EN Control register description explanation this input function. LED_EN internal 800k pulldown resistor AGND. Blank Signal. Assert GSMB reduce current regulator settings according values programmed into GSMB_CUR register. status flash safety timer flash/movie mode values current regulator registers affected GSMB state. Connect GSMB module enable signal other suitable logic signal that indicates transmit process. Polarity this signal GSMB_CUR register (default active-high). GSMB internal 800k pulldown resistor AGND. Data Input. Data read rising edge data clocked falling edge SCL. FLED2 Current Regulator. Current flowing into FLED2 based internal registers FLASH2_CUR MOVIE_CUR. Connect FLED2 cathode external flash module. FLED2 high impedance during shutdown. unused, connect FLED2 ground. FLED1 Current Regulator. Current flowing into FLED1 based internal registers FLASH1_CUR MOVIE_CUR. Connect FLED1 cathode external flash module. FLED1 high impedance during shutdown. unused, connect FLED1 ground. INDLED Current Regulator. Current flowing into INDLED based internal registers IND_CUR. Connect INDLED cathode external indicator LED. INDLED high impedance during shutdown. unused, connect INDLED ground. Bias Output. provides bias thermistor. voltage compared trip threshold programmed NTC_CNTL register. high impedance during shutdown. Connect used. Finger-Burn Protection (NTC) section details.
MAX8834Y/MAX8834Z
PGND
AGND COMP FGND LED_EN
GSMB
FLED2
FLED1
INDLED
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Detailed Description
MAX8834Y/MAX8834Z flash drivers integrate adaptive 1.5A step-up DC-DC converter, 750mA white camera flash/movie current regulators, 16mA indicator current regulator. interface controls individual output on/off, stepup output voltage setting, movie/flash current, flash timer duration settings. Tables movie mode provides continuous lighting when enabled through LED_EN. When flash mode enabled, flash safety timer, programmable from 50ms 800ms through I2C, limits duration flash mode. Once flash safety timer expires, current regulators return movie mode movie mode active when flash event triggered. flash mode priority over movie mode.
Step-Up Converter (LX, OUT, COMP, PGND)
MAX8834Y/MAX8834Z include fixed-frequency, step-up converter that supplies power flash LEDs. output voltage programmable from 3.7V 5.2V 100mV steps) through interface. output voltage also adaptively based forward voltage. step-up converter switches internal power MOSFET synchronous rectifier constant 2MHz 4MHz frequency, with varying duty cycle 75%, maintain constant output voltage input voltage load vary. Internal circuitry prevents unwanted subharmonic switching forcing minimum (typ) duty cycle. When step-up converter dropout mode, internal synchronous rectifier driven fully keeping voltage equal input. This mode provides lowest current consumption when driving LEDs with forward voltage. output voltage internally monitored fault condition. output voltage drops below (typ) nominal programmed value, fault indicated STATUS1 register This feature disabled step-up converter operate adaptive mode.
Flash Safety Timer flash safety timer activated time flash mode selected, either with LED_EN through interface. flash safety timer, programmable from 50ms 800ms through I2C, limits duration flash mode case LED_EN stuck high command turn been sent within programmed flash safety timer duration. This timer configured operate either one-shot mode maximum flash duration mode (see Table one-shot mode, flash function initiated rising edge LED_EN bit) terminated based programmed value safety timer (see Figure maximum flash timer mode, flash function remains enabled long LED_EN bit) high, unless preprogrammed safety timer times (see Figure Once flash mode disabled, either LED_EN, I2C, flash safety timer, flash minimum time (flash safety timer reset inhibit period), before reinitiated (see Figure This prevents spurious events from re-enabling flash mode.
Indicator Current Regulator (INDLED)
low-dropout linear current regulator from INDLED FGND sinks current from cathode terminal indicator LED. INDLED current regulated programmable levels 16mA. Programmable control provided ramp-up (OFF rampdown OFF) times, well blink rate duty cycle. user choose enable disable ramp time blink rate features. Tables more information.
Overvoltage Protection
MAX8834Y/MAX8834Z include comparator monitor output voltage during adaptive mode operation step-up converter. anytime output voltage exceeds maximum threshold 5.5V, COMP capacitor discharged until output voltage reduced 200mV (typ) hysteresis. Once output voltage drops below this threshold, normal charging COMP capacitor resumed.
Flash Current Regulator (FLED1 FLED2)
low-dropout linear current regulator from FLED1/ FLED2 FGND sinks current from cathode terminal flash LED(s). FLED1/FLED2 current regulated programmable levels movie mode 125mA, Table flash mode 750mA,
INDLED Blink Function INDLED current regulator able generate blink function. time INDLED using interface. Figure INDLED Ramp Function INDLED current regulator output provides ramp-up/ down smooth transition between different brightness settings. ramp-up/down times controlled
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
ENABLING FLASH MODE LED_EN CONTROL
ONE-SHOT FLASH TIMER ONE-SHOT FLASH TIMER
Figure One-Shot Flash-Timer Mode
ENABLING FLASH MODE LED_EN CONTROL
MAXIMUM FLASH SAFETY TIMER MAXIMUM FLASH TIMER
Figure Maximum Flash-Timer Mode
ENABLING FLASH MODE LED_EN CONTROL 30ms
Figure Flash Safety Timer Reset Inhibit Period
IIND[4:0]
tIND_OFF
tIND_ON
Figure Blink Function Timing
IND_RU IND_RD control bits, ramp function enabled/disabled IND_RP_EN bit. current regulator increases/decreases current onestep every tRAMP/32 until IND[4:0] current reached. Figures
Combining BLINK Timer Ramp Function When using ramp function INDLED together with blink timer, keep ramp-up timer shorter than blink timer ramp-down timer shorter than timer. Failing comply with this results
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
IINDLED FULL SCALE IINDLED SCALE 128ms 256ms 512ms 1024ms
Figure Ramp-Up Behavior
IINDLED FULL SCALE IINDLED SCALE 128ms 256ms 512ms 1024ms
Figure Ramp-Down Behavior
tIND_OFF
tIND_ON
tIND_OFF
tIND_ON
tIND_OFF
IIND_LED IND_LED[4:0] IIND_LED CODE 0111 IIND_LED CODE 0011 IIND_LED tIND_RU tIND_RD
Figure Combining RAMP Function Blink Timer
programmed current being reached during time, INDLED current returning during time. Figure tIND tIND (IND (IND
FLED1/FLED2 enabled both movie flash modes same time, flash mode priority. Once safety timer expires, current regulator then returns movie mode.
Watchdog Timer
MAX8834Y/MAX8834Z include watchdog timer function that programmed using interface from seconds seconds with 4-second step. watchdog timer expires, MAX8834Y/ MAX8834Z interpret indication that system longer responding enters safe mode. safe mode, MAX8834Y/MAX8834Z disable current regulators step-up DC-DC converter prevent potential damage system. setting respective registers does change, therefore, resetting watchdog timer reverts MAX8834Y/ MAX8834Z back state present before entering safe mode.
tIND
tIND
where IND_LED code from specified IND_LED[4:0].
Enable Input (LED_EN)
LED_EN logic input enable/disable FLED1, FLED2, INDLED current regulators. programmed control movie mode, flash mode, indicator mode using IND_EN, MOVIE_EN, FLASH_EN bits, respectively. Table more information.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
WATCHDOG TIMEOUT SUSPENDING CURRENT REGULATIONS WDT_RST CLEARED
WATCHDOG TIMER ENABLED
WATCHDOG TIMER RESET
WATCHDOG TIMER RESET
WATCHDOG TIMER RESET
(I2C) WDT_EN (I2C) WDT_RST
WATCHDOG TIMER
LED_EN
IFLED_ IINDLED
WDT_DUR[1:0]
WDT_DUR[1:0]
WDT_DUR[1:0]
WDT_DUR[1:0]
Figure Watchdog Timer Timing Diagram
WATCHDOG TIMER ENABLED
WATCHDOG TIMER RESET
WATCHDOG TIMER RESET WDT_RST CLEARED
WATCHDOG TIMEOUT SUSPENDING CURRENT REGULATIONS
WATCHDOG TIMER RESET
(I2C) WDT_EN (I2C) WDT_RST
WATCHDOG TIMER
LED_EN
IFLED_ IINDLED
WDT_DUR[1:0]
WDT_DUR[1:0]
WDT_DUR[1:0]
WDT_DUR[1:0]
Figure Watchdog Timer Timing Diagram
Setting WDT_EN TMR_DUR register (Table enables watchdog timer. Resetting watchdog timer achieved rising falling edge
LED_EN setting WDT_RST register (Table 14). Figures examples watchdog timer timing diagrams.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
GSMB EVENT GSMB (ACTIVE-HIGH)
INPUT CURRENT PREDEFINED INPUT CURRENT LIMIT DURING GSMB
FLED1/FLED2 DECREASED SINCE ILIM[3:0] FLED1/FLED2 INCREASED SINCE ILIM[3:0]
FLED2 OUTPUT CURRENT
FLED1 OUTPUT CURRENT
FLASH1_CUR SETTING
TIME HC_TMR[1:0] AFTER GSMB ACTIVATED, FLED_ GOES MINIMUM SETTING AFTER GSMB DEACTIVATED, FLED_ GOES PREVIOUS SETTING
Figure Input Current Limit During GSMB Event
Blank Function (GSMB)
GSMB input provided allow flash current momentarily reduced during transmit reduce peak current drawn from battery. input current limit ensures that maximum possible output current always provided, regardless input voltage forward voltages. When GSMB event triggered, FLED1 FLED2 current regulators lowest setting ensure current drawn from battery quickly reduced safe level. MAX8834Y/MAX8834Z
then start increasing FLED1 FLED2 current steps, time interval HC_TMR[1:0] (see Table 11). increasing continues until either predefined FLED1/FLED2 current setting reached input current exceeds maximum predefined input current limit during GSMB event. When input current exceeds predefined input current limit, FLED1/FLED2 current reduced LSB. MAX8834Y/MAX8834Z continue adjust FLED1 FLED2 down depending input current limit long GSMB event present. Figure more detailed information.
Adaptive Step-Up Converters with 1.5A Flash Driver
this feature, connect logic signal used enable equivalent, GSMB input. Assertion this signal does change current status flash safety timer flash current values stored registers. Once signal deasserted, current regulators change back their previously programmed values. Polarity this signal controlled through GSMB_CUR register (Table 11). default active-high. plus predefined hysteresis LB_HYS still below VLB_TH VLB_HYS, FLED1/FLED2 current regulators reduce their output current again ensure that minimum input voltage available system. input voltage above VLB_TH VLB_HYS, current regulator increases output current step less than user-defined output current). disable hysteresis, LB_HYS[1:0] this case, after FLED1/FLED2 current reduced, stays current setting. Figures show examples MAXFLASH function operation. Tables control register details. MAXFLASH function continues entire duration FLASH/MOVIE event ensure that FLASH/MOVIE output current always maximized specific operating conditions.
MAX8834Y/MAX8834Z
Finger-Burn Protection (NTC)
input provided (optional) finger-burn protection feature. this feature, connect 100k with 4550 between AGND. sources 20µA current voltage established this current resistance compared internally voltage threshold range 200mV 550mV, programmed through bits [2:0] Control register (see Table 10). voltage falls below programmed threshold during flash event, flash cycle immediately terminated, indication latched through STATUS1 register (see Table 15). disable this function, clear (enable bit) Control register.
Undervoltage Lockout
MAX8834Y/MAX8834Z contain undervoltage lockout (UVLO) circuitry that disables until greater than 2.3V (typ). Once rises above 2.3V (typ), UVLO circuitry does disable until falls below UVLO threshold minus hysteresis voltage. MAX8834Y/MAX8834Z also contain UVLO circuitry that monitors voltage. When voltage falls below 1.4V (typ), contents logic registers reset their default states. logic registers only reset UVLO condition UVLO condition.
MAXFLASH Function
During high load currents, battery voltage momentarily drops internal ESR, together with serial impedance from battery load. equipment requiring minimum voltage stable operation, battery needs calculated estimate maximum battery current that maintains battery voltage above critical threshold. complicated measurement battery ESR, MAX8834Y/MAX8834Z feature MAXFLASH function prevent battery voltage from dropping below threshold voltage. Figure details. MAX8834Y/MAX8834Z input voltage monitored during FLASH/MOVIE event. input voltage drops below predefined threshold (VLB_TH), indicates that FLASH/MOVIE event drawing more current than battery support. result, FLED1/FLED2 current regulators start decreasing their output currents step. Therefore, input current reduced input voltage starts rise internal battery ESR. input voltage then sampled again after tLB_TMR compared VLB_TH
tLB_TMR
IOUT_MAX
DOWN
VLB_TH
CURRENT REGULATOR
VLB_HYS VLB_TH
Figure Block Diagram MAXFLASH Function
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
VLB_TH VLB_HYS
VLB_TH
tLB_TMR TIME
Figure Example MAXFLASH Function Operation
REDUCTION BATTERY CURRENT CAUSED OTHER SYSTEM
VLB_TH VLB_HYS
VLB_TH
IMAX
tLB_TMR
TIME
Figure Example MAXFLASH Function Operation
REDUCTION BATTERY CURRENT CAUSED OTHER SYSTEM
FLASH CURRENT INCREASED AGAIN SINCE LB_HYS
VLB_TH VLB_HYS
VLB_TH
IMAX
tLB_TMR TIME
Figure Example MAXFLASH Function Operation with Hysteresis Disabled
FLASH/MOVIE CURRENT
BATTERY VOLTAGE
FLASH/MOVIE CURRENT
BATTERY VOLTAGE
FLASH/MOVIE CURRENT
BATTERY VOLTAGE
Adaptive Step-Up Converters with 1.5A Flash Driver
Soft-Start
step-up converter implements soft-start control inrush current when turns soft-starts charging CCOMP with 100µA current source. During this time, internal MOSFET switching minimum duty cycle. Once COMP rises above duty cycle increases until output voltage reaches desired regulation level. COMP pulled AGND with (typ) internal resistor during UVLO, dropout mode, shutdown. Typical Operating Characteristics example soft-start operation. Soft-start reinitiated after UVLO step-up converter reenabled after shutdown dropout mode. FLED2 regulators must disabled through avoid fault detection from open short.
MAX8834Y/MAX8834Z
Open/Short Detection
MAX8834Y/MAX8834Z monitor FLED1, FLED2, INDLED voltage detect open short LEDs. short fault detected when voltage rises above VOUT (typ), open fault detected when voltage falls below 100mV. fault detection circuitry only activated when corresponding current regulator enabled provides continuous monitor current regulator condition. Once fault detected, corresponding current regulator disabled status latched into corresponding fault register (see Table 15). This allows processor determine MAX8834Y/MAX8834Z operating condition.
Shutdown Standby
MAX8834Y/MAX8834Z shutdown when either UVLO. shutdown, supply current reduced 0.1µA (typ). When above UVLO threshold, below UVLO threshold, disables internal reference, keeps registers reset, turns step-up converter off, turns FLED1/FLED2 current regulators (high impedance). Once logic-level voltage supplied VDD, enters standby condition ready accept commands. internal MOSFET, synchronous rectifier, FLED1/FLED2 also high impedance standby. Typical shutdown timing characteristics shown Typical Operating Characteristics.
Thermal Shutdown
Thermal shutdown limits total power dissipation MAX8834Y/MAX8834Z. When junction temperature exceeds +160°C (typ), turns off, allowing itself cool. turns begins soft-start after junction temperature cools 20°C. This results pulsed output during continuous thermal overload conditions.
Parallel Connection Current Regulators
FLED1/FLED2 current regulators connected parallel long system software properly sets current levels each regulator. Unused current regulators connected ground. FLED1/
Serial Interface I2C-compatible, 2-wire serial interface controls step-up converter output voltage, flash, movie, indicator current settings, flash duration, other parameters. serial consists bidirectional serial-data line (SDA) serial-clock input (SCL). MAX8834Y/MAX8834Z slave-only devices, relying upon master generate clock signal. master initiates data transfer from MAX8834Y/
tSU,STA tHD,DAT tHIGH tBUF tHD,STA tSU,STO
tLOW
tSU,DAT
tHD,STA START CONDITION
REPEATED START CONDITION STOP CONDITION START CONDITION
Figure 2-Wire Serial Interface Timing Detail
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
START CONDITION
DATA LINE STABLE DATA VALID
DATA ALLOWED CHANGE
STOP CONDITION
Figure Transfer
MAX8834Z generates synchronize data transfer (Figure 15). open-drain bus. Both bidirectional lines, connected positive supply voltage through pullup resistor. They both have Schmitt triggers filter circuits suppress noise spikes assure proper device operation. master initiates communication with MAX8834Y/MAX8834Z slave device issuing START condition followed MAX8834Y/ MAX8834Z address. MAX8834Y/MAX8834Z address byte consists address bits read/ write (R/W). After receiving proper address, MAX8834Y/MAX8834Z issue acknowledge pulling during ninth clock cycle.
START STOP Conditions Both remain high when busy. master signals beginning transmission with START condition transitioning from high while high. When master finished communicating with MAX8834Y/ MAX8834Z, issues STOP condition transitioning from high while high. then free another transmission (Figure 17). Both START STOP conditions generated master. Acknowledge acknowledge used recipient handshake receipt each byte data (Figure 18). After data transfer, master generates acknowledge clock pulse recipient pulls down line during this acknowledge clock pulse line stays during high duration clock pulse. When master transmits data MAX8834Y/MAX8834Z, releases line MAX8834Y/MAX8834Z take control line generate acknowledge bit. When remains high during this clock pulse, this defined acknowledge signal. master then generate either STOP condition abort transfer, repeated START condition start transfer.
Slave Address MAX8834Y/MAX8834Z slave transmitter/ receiver. slave address 0x94 write operations 0x95 read operations. Transfer Each data bit, from most significant least significant bit, transferred during each clock cycle. During data transfer, signal allowed change only during period clock must remain stable during high period clock (Figure 16).
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
MASTER ACKNOWLEDGE SLAVE
ACKNOWLEDGE
START CONDITION
STOP CONDITION
START CONDITION
CLOCK PULSE ACKNOWLEDGEMENT
Figure START STOP Conditions
Figure Acknowledge
Write Operations MAX8834Y/MAX8834Z recognize write byte protocol defined SMBusspecification shown section Figure write byte protocol allows master device send byte data slave device. write-byte protocol requires register pointer address subsequent write. MAX8834Y/MAX8834Z acknowledge register pointer even though only subset those registers actually exists device. write byte protocol follows: master sends start command.
master sends 7-bit slave address followed write bit. addressed slave asserts acknowledge pulling low. master sends 8-bit register pointer. slave acknowledges register pointer. master sends data byte. slave updates with data. slave acknowledges data byte. master sends STOP condition. addition write-byte protocol, MAX8834Y/ MAX8834Z write multiple registers shown section Figure This protocol allows master device address slave only once then send data sequential block registers starting specified register pointer.
following procedure write sequential block registers: master sends start command. master sends 7-bit slave address followed write bit. addressed slave asserts acknowledge pulling low. master sends 8-bit register pointer first register write. slave acknowledges register pointer. master sends data byte. slave updates with data. slave acknowledges data byte. Steps repeated many registers block, with register pointer automatically incremented each time. master sends STOP condition.
Read Operations method reading single register (byte) shown section Figure read single register: master sends start command.
master sends 7-bit slave address followed write bit. addressed slave asserts acknowledge pulling low. master sends 8-bit register pointer.
SMBus trademark Intel Corp.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
LEGEND MASTER SLAVE SLAVE MASTER
WRITING SINGLE REGISTER WITH WRITE BYTE PROTOCOL
SLAVE ADDRESS
REGISTER POINTER
DATA
NUMBER BITS
WRITING MULTIPLE REGISTERS
SLAVE ADDRESS
REGISTER POINTER
DATA
DATA
NUMBER BITS
DATA X+n-1
DATA
NUMBER BITS
Figure Writing MAX8834Y/MAX8834Z
slave acknowledges register pointer. master sends REPEATED START (Sr) condition. master sends 7-bit slave address followed read bit. slave asserts acknowledge pulling low. slave sends 8-bit data (contents register). master asserts acknowledge pulling low. master sends STOP condition. addition, MAX8834Y/MAX8834Z read block multiple sequential registers shown section Figure following procedure read sequential block registers: master sends start command. master sends 7-bit slave address followed write bit.
addressed slave asserts acknowledge pulling low. master sends 8-bit register pointer first register block. slave acknowledges register pointer. master sends REPEATED START condition. master sends 7-bit slave address followed read bit. slave asserts acknowledge pulling low. slave sends 8-bit data (contents register). master asserts acknowledge pulling low. Steps repeated many registers block, with register pointer automatically incremented each time. master sends STOP condition.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
LEGEND MASTER SLAVE SLAVE MASTER
READING SINGLE REGISTER
SLAVE ADDRESS
REGISTER POINTER
SLAVE ADDRESS
DATA
NUMBER BITS
READING MULTIPLE REGISTERS
SLAVE ADDRESS
REGISTER POINTER
SLAVE ADDRESS
DATA
NUMBER BITS
DATA
DATA X+n-1
DATA
NUMBER BITS
Figure Reading from MAX8834Y/MAX8834Z
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table Register
NAME BOOST_CNTL FLASH1_CUR FLASH2_CUR MOVIE_CUR Reserved future IND_CUR Reserved future IND_CNTL Reserved future LED_CNTL TMR_DUR NTC_CNTL GSMB_CUR MAXFLASH1 MAXFLASH2 WDT_RST STATUS1 STATUS2 Reserved future CHIP_ID1 CHIP_ID2 TABLE Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table REGISTER ADDRESS (hex) TYPE DESCRIPTION Step-up converter control FLED1 flash current control FLED2 flash current control FLED1 FLED2 movie current control Reserved future Indicator current control Reserved future Indicator ramp blink control Reserved future FLED1, FLED2, INDLED on/off mode control, definition LED_EN logic input function Watchdog timer flash safety timer control function control FLED1 FLED2 current control during transmit MAXFLASH function register MAXFLASH function register Watchdog timer reset Status register Status register Reserved future type information type mask revision information
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table BOOST_CNTL
This register contains step-up converter control values.
REGISTER NAME Address Reset Value Type Special Features BOOST_CNTL 0x00 0x00 Read/write
(MSB)
NAME BOOST_EN Reserved future Step-up converter Step-up converter
DESCRIPTION
DEFAULT VALUE
BOOST_MODE
Step-up voltage adaptively Step-up voltage programmatically according BOOST_CNTL[3:0] Step-up converter runs dropout Step-up converter automatically changes between adaptive regulation dropout mode depending operating conditions 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 3.7V 3.8V 3.9V 4.0V 4.1V 4.2V 4.3V 4.4V 4.5V 4.6V 4.7V 4.8V 4.9V 5.0V 5.1V 5.2V
BOOST_CNTL[3:0]
0000
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table FLASH1_CUR
This register contains FLED1 flash current control values.
REGISTER NAME Address Reset Value Type Special Features FLASH1_CUR 0x01 0x00 Read/write
NAME
DESCRIPTION FLED1 Flash Mode Current Setting 00000 23.44mA 00001 46.88mA 00010 70.32mA 00011 93.76mA 00100 117.20mA 00101 140.64mA 00110 164.08mA 00111 187.52mA 01000 210.96mA 01001 234.40mA 01010 257.84mA 01011 281.28mA 01100 304.72mA 01101 328.16mA 01110 351.60mA 01111 375.04mA 10000 398.48mA 10001 421.92mA 10010 445.36mA 10011 468.80mA 10100 492.24mA 10101 515.68mA 10110 539.12mA 10111 562.56mA 11000 586.00mA 11001 609.44mA 11010 632.88mA 11011 656.32mA 11100 679.76mA 11101 703.20mA 11110 726.56mA 11111 750.00mA Reserved future Reserved future Reserved future
DEFAULT VALUE
(MSB)
FLASH1[4:0]
00000
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table FLASH2_CUR
This register contains FLED2 flash current control values.
REGISTER NAME Address Reset Value Type Special Features FLASH2_CUR 0x02 0x00 Read/write
NAME
DESCRIPTION FLED2 Flash Mode Current Setting 00000 23.44mA 00001 46.88mA 00010 70.32mA 00011 93.76mA 00100 117.20mA 00101 140.64mA 00110 164.08mA 00111 187.52mA 01000 210.96mA 01001 234.40mA 01010 257.84mA 01011 281.28mA 01100 304.72mA 01101 328.16mA 01110 351.60mA 01111 375.04mA 10000 398.48mA 10001 421.92mA 10010 445.36mA 10011 468.80mA 10100 492.24mA 10101 515.68mA 10110 539.12mA 10111 562.56mA 11000 586.00mA 11001 609.44mA 11010 632.88mA 11011 656.32mA 11100 679.76mA 11101 703.20mA 11110 726.56mA 11111 750.00mA Reserved future Reserved future Reserved future
DEFAULT VALUE
(MSB)
FLASH2[4:0]
00000
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table MOVIE_CUR
This register contains FLED1 FLED2 movie current control values.
REGISTER NAME Address Reset Value Type Special Features MOVIE_CUR 0x03 0x00 Read/write
(MSB)
NAME Reserved future
DESCRIPTION FLED1 Movie Mode Current Setting 15.625mA 31.250mA 49.875mA 62.500mA 78.125mA 93.750mA 109.375mA 125.000mA Reserved future FLED2 Movie Mode Current Setting 15.625mA 31.250mA 49.875mA 62.500mA 78.125mA 93.750mA 109.375mA 125.000mA
DEFAULT NAME
MOVIE1[2:0]
MOVIE2[2:0]
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver
Table IND_CUR
This register contains indicator current control values.
REGISTER NAME Address Reset Value Type Special Features (MSB) NAME IND_BL_EN Reserved future INDLED Indicator Blink Timer Enable Indicator blink disabled Indicator blink enabled INDLED Indicator Ramp-Up/Down Enable Indicator ramp-up/down disabled Indicator ramp-up/down enabled INDLED Indicator Mode Current Setting 00000 0.5mA 00001 1.0mA 00010 1.5mA 00011 2.0mA 00100 2.5mA 00101 3.0mA 00110 3.5mA 00111 4.0mA 01000 4.5mA 01001 5.0mA 01010 5.5mA 01011 6.0mA 01100 6.5mA 01101 7.0mA 01110 7.5mA 01111 8.0mA 10000 8.5mA 10001 9.0mA 10010 9.5mA 10011 10.0mA 10100 10.5mA 10101 11.0mA 10110 11.5mA 10111 12.0mA 11000 12.5mA 11001 13.0mA 11010 13.5mA 11011 14.0mA 11100 14.5mA 11101 15.0mA 11110 15.5mA 11111 16.0mA IND_CUR 0x05 0x00 Read/write DESCRIPTION DEFAULT VALUE
MAX8834Y/MAX8834Z
IND_RP_EN
IND[4:0]
00000
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table IND_CNTL
This register contains indicator ramp blink timer control.
REGISTER NAME Address Reset Value Type Special Features (MSB) IND_OFF IND_ON NAME IND_CNTL 0x07 0x00 Read/write DESCRIPTION INDLED Indicator Blink Timer Control 512ms 1024ms 2048ms 4096ms INDLED Indicator Blink Timer Control 128ms 256ms 512ms 1024ms INDLED Indicator Ramp-Up Timer Control 128ms 256ms 512ms 1024ms INDLED Indicator Ramp-Down Timer Control 128ms 256ms 512ms 1024ms DEFAULT VALUE
IND_RU[1:0]
IND_RD[1:0] (LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table LED_CNTL
This register contains FLED1, FLED2 INDLED on/off mode control.
REGISTER NAME Address Reset Value Type Special Features (MSB) IND_EN[1:0] NAME LED_CNTL 0x09 0x00 Read/write DESCRIPTION INDLED Indicator Current Regulator Enable INDLED indicator disabled INDLED indicator disabled INDLED indicator enabled INDLED indicator controlled LED_EN input FLED1/FLED2 MOVIE Mode Current Regulator Enable FLED1 FLED2 movie mode disabled FLED1 movie mode enabled, FLED2 movie mode disabled FLED2 movie mode enabled, FLED1 movie mode disabled FLED1 FLED2 movie mode enabled FLED1 movie mode controlled LED_EN, FLED2 movie mode disabled FLED2 movie mode controlled LED_EN, FLED1 movie mode disabled FLED1 FLED2 movie mode controlled LED_EN FLED1/FLED2 Flash Mode Current Regulator Enable FLED1 FLED2 flash mode disabled FLED1 flash mode enabled, FLED2 flash mode disabled FLED2 flash mode enabled, FLED1 flash mode disabled FLED1 FLED2 flash mode enabled FLED1 flash mode controlled LED_EN, FLED2 flash mode disabled FLED2 flash mode controlled LED_EN, FLED1 flash mode disabled FLED1 FLED2 flash mode controlled LED_EN DEFAULT VALUE
MOVIE_EN[2:0]
FLASH_EN[2:0]
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table TMR_DUR
This register contains watchdog timer flash safety time-control values.
REGISTER NAME Address Reset Value Type Special Features (MSB) WDT_DUR[1:0] NAME WDT_EN TMR_DUR 0x0A 0x00 Read/write DESCRIPTION Enable/Disable Watchdog Timer Function disabled enabled Watchdog Timer Duration Safety Timer Control One-shot mode-generates flash with duration TMR_DUR regardless LED:EN setting; pulling this condition terminates flash operating puts into power-down mode Maximum timer mode-ensures that flash duration does exceed timer defined TMR:DUR Safety Timer Duration Control 0000 50ms 0001 100ms 0010 150ms 0011 200ms 0100 250ms 0101 300ms 0110 350ms 0111 400ms 1000 450ms 1001 500ms 1010 550ms 1011 600ms 1100 650ms 1101 700ms 1110 750ms 1111 800ms DEFAULT VALUE
TMR_MODE
TMR_DUR [3:0]
0000
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table NTC_CNTL
This register contains function control values.
REGISTER NAME Address Reset Value Type Special Features NAME NTC_CNTL 0x0B 0x00 Read/write DESCRIPTION DEFAULT VALUE
(MSB)
Flash Safety Timer Reset Control Enable FLASH reset timer, only valid when FLASH mode enabled using LED_EN; LED_EN needs pulled FLASH_TMR_CNTL minimum 30ms (typ) reset flash safety Disable FLASH reset timer; flash safety timer reset soon LED_EN pulled Reserved future NTC_EN Reserved future Reserved future Finger-Burn Feature Enable Disable function Enable function Finger-Burn Threshold Control 200mV 250mV 300mV 350mV 400mV 450mV 500mV 550mV
NTC[2:0]
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table GSMB_CUR
This register contains FLED1 FLED2 current control values GSMB function.
REGISTER NAME Address Reset Value Type Special Features (MSB) NAME GSMB_EN Blank Enable GSMB input disabled GSMB input enabled Blank Polarity Control GSMB active-low GSMB active-high Input Current Limit During GSMB 0000 50mA 0001 100mA 0010 150mA 0011 200mA 0100 250mA 0101 300mA 0110 350mA 0111 400mA 1000 450mA 1001 500mA 1010 550mA 1011 600mA 1100 650mA 1101 700mA 1110 750mA 1111 800mA GSMB Reset Timer GSMB_CUR 0x0C 0xC0 Read/write DESCRIPTION DEFAULT VALUE
GSMB_POL
ILIM[3:0]
0000
HC_TMR[1:0] (LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver
Table MAXFLASH1
This register contains MAXFLASH control function.
REGISTER NAME Address Reset Value Type Special Features (MSB) NAME LB_EN MAXFLASH1 0x0D 0x00 Read/write DESCRIPTION MAXFLASH Function Enable Disabled Low-battery function enabled Low-Battery Detection Threshold 00000 2.400V use] 00001 2.433V use] 00010 2.466V use] 00011 2.500V 00100 2.533V 00101 2.566V 00110 2.600V 00111 2.633V 01000 2.666V 01001 2.700V 01010 2.733V 01011 2.766V 01100 2.800V 01101 2.833V 01110 2.866V 01111 2.900V 10000 2.933V 10001 2.966V 10010 3.000V 10011 3.033V 10100 3.066V 10101 3.100V 10110 3.133V 10111 3.166V 11000 3.200V 11001 3.233V 11010 3.266V 11011 3.300V 11100 3.333V 11101 3.366V 11110 3.400V 11111 3.400V Low-Battery Detection Hysteresis 100mV 200mV Reserved future Hysteresis disabled-flash current only reduced DEFAULT VALUE
MAX8834Y/MAX8834Z
LB_TH[4:0]
00000
LB_HYS[1:0] (LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table MAXFLASH2
This register contains MAXFLASH control function.
REGISTER NAME Address Reset Value Type Special Features (MSB) LB_TMR[1:0] (LSB) NAME Reserved future Reserved future Reserved future Reserved future Reserved future Reserved future Low-Battery Reset Timer 0.250ms 0.500ms Reserved future Reserved future MAXFLASH2 0x0E 0x00 Read/write DESCRIPTION DEFAULT VALUE
Table WDT_RST
This register contains watchdog reset function.
REGISTER NAME Address Reset Value Type Special Features (MSB) NAME Reserved future Reserved future Reserved future Reserved future Reserved future Reserved future Reserved future Watchdog Reset Default Writing resets watchdog timer; after writing this cleared upon watchdog timer reset WDT_RST 0x16 0x00 Read/write DESCRIPTION DEFAULT VALUE
(LSB)
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table STATUS1
This register contains status information.
REGISTER NAME Address Reset Value Type Special Features (MSB) NAME NTC_FLT STATUS1 0x17 Read DESCRIPTION Status Readback status Fault (short) occurred GSMB Status Readback GSMB event occurred GSMB event occurred Window Cooperator Status Readback Output voltage within window fault occurred Temperature Overload Condition Status Readback temp within spec overtemp event occurred Status Readback temperature within spec temperature threshold tripped INDLED Status Readback INDLED status Fault (open/short) occurred INDLED FLED2 Status Readback FLED2 status Fault (open/short) occurred FLED2 FLED1 Status Readback FLED1 status Fault (open/short) occurred FLED1 DEFAULT VALUE
GSMB
POK_FLT
OVER_TEMP
NTC_OVT
INDLED_FLT
FLED2_FLT
(LSB)
FLED1_FLT
Note: faults latched. Bit(s) cleared after reading register contents. fault still present, again.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table STATUS2
This register contains status information.
REGISTER NAME Address Reset Value Type Special Features NAME STATUS2 0x18 Read DESCRIPTION Indication MAXFLASH Function Been Triggered Since Last Read Operation This Register MAXFLASH event occurred MAXFLASH event occurred Indication Input Current Limit Been Reached During GSMB Since Last Read Operation This Register Input current limit reached Input current limit reached Reserved future Reserved future Reserved future Reserved future Reserved future Reserved future DEFAULT VALUE
(MSB)
MAXFLASH_STAT
(LSB)
GSMB_ILIM
Table CHIP_ID1
This register contains MAX8834Y/MAX8834Z type number.
REGISTER NAME Address Reset Value Type Special Features (MSB) (LSB) DIE_TYPE[3:0] Character [0001] DIE_TYPE[7:4] Character [0001] NAME CHIP_ID1 0x1A Read DESCRIPTION DEFAULT VALUE
Note: This register value fixed metal.
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table CHIP_ID2
This register contains type dash number plain) mask revision level.
REGISTER NAME Address Reset Value Type Special Features (MSB) (LSB) MASK_REV Character representing revision DASH Character representing dash number NAME CHIP_ID2 0x1B Read DESCRIPTION DEFAULT VALUE
Applications Information
Inductor Selection
Table list recommended inductors. prevent core saturation, ensure that inductor saturation current rating exceeds peak inductor current application. Calculate worst-case peak inductor current follows: IPEAK VOUT IOUT(MAX) VIN(MIN) VIN(MIN)
most situations, 4.7µF ceramic capacitor acceptable lower load currents.
Compensation Network Selection
step-up converter compensated stability through external compensation network from COMP AGND. Table recommended compensation networks.
Layout
fast-switching waveforms high-current paths, careful layout required. Connect AGND, FGND, PGND directly ground plane. bypass capacitor should placed close possible RCOMP CCOMP should connected between COMP AGND close possible Minimize trace lengths between inductor, input capacitor, output capacitor; keep these traces short, direct, wide. ground connections should close together possible connected PGND. traces from input inductor from output capacitor LEDs longer. Figure illustrates example layout routing scheme. Refer MAX8834Y/MAX8834Z Evaluation layout example.
where switching frequency.
Capacitor Selection
Bypass AGND PGND with ceramic capacitor. Ceramic capacitors with dielectrics recommended their tighter tolerances over wide temperature ranges. Place capacitor close possible recommended minimum value input capacitor 10µF; however, larger value capacitors used reduce input ripple expense size higher cost. output capacitance required depends output current. 10µF ceramic capacitor works well
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Table Suggested Inductors
MANUFACTURER PART/SERIES LPS4012-222ML LPS4018-222ML LPS5030-220ML LPS6225-222ML LPO3310-102ML LPS3015-102ML Coilcraft LPO3010-102NLC DO3314-102ML LPS3314-102ML DP1605T-102ML LPS4012-102ML LPS4018-102ML LPS5015-102ML NR4018T2R2M NR3012T1R0N NR4010T1R0N Taiyo Yuden NR3015T1R0N NR4012T1R0N NP03SB1R0M NP04SZB1R0N NR4018T1R0N 1117AS-1R2N 1098AS-1R2N TOKO A997AS-1R0N 1072AS-1R0N 1071AS-1R0N INDUCTANCE ISAT 1.95 DIMENSIONS (lTYP HMAX) (mm) 3x3x1 3x3x1 3x3x1 4x4x1 5x5x2 3x3x1
Table Suggested Compensation Networks
INDUCTANCE 1.0H Inductor (dynamic loads) 2.2H Inductor (dynamic loads) 4.7H Inductor (dynamic loads) Inductor (dynamic loads) Other (non-LED) Loads 10H) RCOMP (short) CCOMP (pF) 2200 2200 4700 6800 22000
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
6.0mm
COUT
COMP CCOMP FLED2 FLASH2 CATHODE
FGND FGND
PGND PGND LED_EN FLED1
GSMB INDLED
AGND CVDD
FLASH1 CATHODE INDICATOR CATHODE
3.8mm
Figure Recommended Layout
Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z
Block Diagram Typical Application Circuit
INPUT CURRENT LIMIT
PROGRAMMABLE OUTPUT 3.7V 5.2V COUT
2.5V 5.5V
AGND PGND COMP CCOMP RCOMP
UVLO POWER
STEP-UP CONVERTER ADAPTIVE/ FIXED OUTPUT SELECT VREF SELECT
2MHz 4MHz
VREG
FLASH TIMER WATCHDOG TIMER REGISTERS CONTROL LOGIC SAMPLING LOGIC
VPOK 750mA FLED1
RNTC 100k VLOGIC 1.62V 3.6V FLASH/MOVIE LED_EN STROBE CVDD 0.1F GSMB PA_EN 1MHz
750mA
FLED2
16mA INDLED
FGND
INTERFACE
INTERFACE
MAX8834Y MAX8834Z
Adaptive Step-Up Converters with 1.5A Flash Driver
Configuration
PROCESS: BiCMOS
VIEW (BUMPS BOTTOM)
Chip Information Package Information
latest package outline information land patterns, www.maxim-ic.com/packages.
MAX8834Y/MAX8834Z
MAX8834Y/MAX8834Z
PGND
PACKAGE TYPE
PACKAGE CODE W202A2+2
DOCUMENT 21-0059
PGND
AGND
COMP
FGND
LED_EN
GSMB
FLED2
FGND
FLED1 (2.5mm 2.0mm)
INDLED
Maxim cannot assume responsibility circuitry other than circuitry entirely embodied Maxim product. circuit patent licenses implied. Maxim reserves right change circuitry specifications without notice time.
Maxim Integrated Products, Gabriel Drive, Sunnyvale, 94086 408-737-7600
2009 Maxim Integrated Products Maxim registered trademark Maxim Integrated Products, Inc.
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