19-4421; Rev 0; 4/09 KIT ATION EVALU LE B A IL A AV Adaptive Step-Up Converters with 1.5A Flash Driver The MAX8834Y/MAX8834Z flash drivers integrate a 1.5A PWM DC-DC step-up converter and three programmable low-side, low-dropout LED current regulators. The step-up converter features an internal switching MOSFET and synchronous rectifier to improve efficiency and minimize external component count. An I2C interface provides flexible control of stepup converter output voltage setting, movie/flash mode selection, flash timer duration settings, and current regulator settings. The MAX8834Y/MAX8834Z operate down to 2.5V, making them future proof for new battery technologies. The MAX8834Y/MAX8834Z consist of two current regulators for the flash/movie mode. Each current regulator can sink 750mA in flash mode and 125mA in movie mode. The MAX8834Y/MAX8834Z also integrate a 16mA lowcurrent regulator that can be used to indicate camera status. The indicator current regulator includes programmable ramp and blink timer settings. A programmable input current limit, invoked using the GSMB control, reduces the total current drawn from the battery during PA transmit events. This ensures the flash current is set to the maximum possible for any given operating condition. Additionally, the MAX8834Y/MAX8834Z include a MAXFLASH* function that adaptively reduces flash current during low battery conditions to help prevent system undervoltage lockup. Other features include an optional NTC input for fingerburn protection and open/short LED detection. The MAX8834Y switches at 2MHz, providing best overall efficiency. The MAX8834Z switches at 4MHz, providing smallest overall solution size. The MAX8834Y/ MAX8834Z are available in a 20-bump, 0.5mm pitch WLP package (2.5mm x 2.0mm). Features ♦ 2.5V to 5.5V Operation Range ♦ Step-Up DC-DC Converter 1.5A Guaranteed Output Current Adaptive or I2C Programmable Output Voltage 2MHz and 4MHz Switching Frequency Options ♦ Two Flash/Movie LED Current Regulators I2C Programmable Flash and Movie Current Low-Dropout Voltage (110mV max) at 500mA ♦ LED Indicator Current Regulator I2C Programmable Output Current Ramp and Blink Timers for Indicator Mode Low-Dropout Voltage (130mV max) at 16mA ♦ I2C Programmable Safety and Watchdog Timers ♦ GSM Blank Logic Input ♦ MAXFLASH System Lockup Protection ♦ Remote Temperature Sensor Input ♦ Open/Short LED Detection ♦ Thermal Shutdown Protection ♦ < 1µA Shutdown Current ♦ 20-Bump, 0.5mm Pitch, 2.5mm x 2.0mm WLP Applications Cell Phones and Smart Phones PDAs, Digital Cameras, and Camcorders Typical Operating Circuit 1μH OR 2.2μH INPUT 2.5V TO 5.5V LX IN 10μF AGND PGND Ordering Information COMP SWITCHING TEMP PIN-PACKAGE FREQUENCY RANGE (MHz) -40°C to 20 WLP MAX8834YEWP+T +85°C (2.5mm x 2.0mm) MAX8834ZEWP+T OUT 10μF *Patent pending. PART PROGRAMMABLE OUTPUT 3.7V TO 5.2V -40°C to 20 WLP +85°C (2.5mm x 2.0mm) 2 PA_TXON 1.5A TOTAL FLASH I2C GSMB VLOGIC 0.1μF INDLED 16mA INDICATOR LED_EN SCL SDA +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. FLED1 FLED2 FLASH ON 4 MAX8834Y MAX8834Z VDD FGND NTC FINGER-BURN PROTECTION Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX8834Y/MAX8834Z General Description MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver ABSOLUTE MAXIMUM RATINGS IN, OUT, NTC to AGND .........................................-0.3V to +6.0V VDD to AGND.........................................................-0.3V to +4.0V SCL, SDA, LED_EN, GSMB to AGND ........-0.3V to (VDD + 0.3V) FLED1, FLED2, INDLED to FGND ............-0.3V to (VOUT + 0.3V) COMP to AGND ...........................................-0.3V to (VIN + 0.3V) PGND, FGND to AGND .........................................-0.3V to +0.3V ILX Current (rms) ......................................................................3A Continuous Power Dissipation (TA = +70°C) (derate 17.5mW/°C above +70°C) .............................1410mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Bump Temperature* (soldering) ......................................+260°C *This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the device can be exposed to during board level solder attach and rework. This limit permits only the use of the solder profiles recommended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and Convection reflow. Preheating is required. Hand or wave soldering is not allowed. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VIN = 3.6V, VAGND = VPGND = VFGND = 0V, VDD = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) MAX UNITS IN Operating Voltage PARAMETER 2.5 5.5 V VDD Operating Range 1.62 3.6 V 1.55 V VDD Undervoltage Lockout (UVLO) Threshold CONDITIONS MIN VDD falling 1.25 1.4 VIN falling 2.15 2.3 VDD UVLO Hysteresis IN UVLO Threshold TYP 50 IN UVLO Hysteresis mV 2.45 50 IN Standby Supply Current VSCL = VSDA = VDD, VIN = 5.5V, I2C ready VDD Standby Supply Current (All Outputs Off, I2C Enabled) VSCL = VSDA = VDD = 3.6V, I2C ready 4 V mV 1 μA 7 μA LOGIC INTERFACE LED_EN, GSMB Logic Input-High Voltage VDD = 1.62V to 3.6V Logic Input-Low Voltage VDD = 1.62V to 3.6V SCL, SDA 1.4 V 0.7 x VDD LED_EN, GSMB 0.4 0.3 x VDD SCL, SDA LED_EN Minimum High Time (LED_EN is Internally Sampled by a 1MHz Clock) LED_EN Propagation Delay From LED_EN going high to rising edge on current regulator LED_EN and GSMB Pulldown Resistor Logic Input Current (SCL, SDA) 2 VIL = 0V or VIH = 3.6V TA = +25°C TA = +85°C V 1 μs 3 μs 400 800 1600 -1 0.01 +1 0.1 _______________________________________________________________________________________ k μA Adaptive Step-Up Converters with 1.5A Flash Driver (VIN = 3.6V, VAGND = VPGND = VFGND = 0V, VDD = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Shutdown Leakage Current CONDITIONS TA = +25°C IN and VDD in UVLO, VLED_EN = VGSMB = 0V MIN TYP MAX -1 0.01 +1 TA = +85°C 0.1 UNITS μA I2C INTERFACE SDA Output Low Voltage I SDA = 3mA 0.03 I2C Clock Frequency Bus-Free Time Between STOP and START tBUF 1.3 Hold Time Repeated START Condition tHD_STA 0.6 0.4 V 400 kHz μs 0.1 μs SCL Low Period tLOW 1.3 0.2 μs SCL High Period tHIGH 0.6 0.2 μs Setup Time Repeated START Condition t SU_STA 0.6 0.1 μs SDA Hold Time tHD_DAT 0 -0.01 μs SDA Setup Time t SU_DAT 100 50 ns Setup Time for STOP Condition t SU_STO 0.6 0.1 μs 100mV steps 3.7 STEP-UP DC-DC CONVERTER OUT Voltage Range OUT Voltage Accuracy No load, VOUT = 5V OUT Overvoltage Protection When running in adaptive mode Adaptive Output Voltage Regulation Threshold IFLED1 = IFLED2 = 492.24mA setting, IINDLED = 16mA 5.2 V -2.75 ±0.5 +2.75 % 5.2 5.35 5.5 V 150 -15 PGOOD Window Comparator VOUT = 5V, in programmable mode Line Regulation VIN = 2.5V to 4.2V 0.1 %/V Load Regulation I OUT = 0mA to 1500mA 0.5 %/A nFET Current Limit -12.5 mV -10 3.6 % A LX nFET On-Resistance LX to PGND, ILX = 200mA 0.055 0.130 LX pFET On-Resistance LX to OUT, ILX = 200mA 0.12 0.200 LX Leakage VLX = 5.5V TA = +25°C 0.1 1 TA = +85°C 0.1 Input Current Limit Range During GSMB Trigger 50 Input Current Limit Step Size During GSMB Trigger Input Current Limit Accuracy 800 50 I ILIM = 100mA, in dropout mode MAX8834Y Operating Frequency, No Load MAX8834Z -15 TA = +25°C 1.8 TA = -40°C to +85°C 1.6 TA = +25°C 3.6 TA = -40°C to +85°C 3.2 μA mA mA +15 2 2.2 4 4.4 2.4 % MHz 4.8 _______________________________________________________________________________________ 3 MAX8834Y/MAX8834Z ELECTRICAL CHARACTERISTICS (continued) MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver ELECTRICAL CHARACTERISTICS (continued) (VIN = 3.6V, VAGND = VPGND = VFGND = 0V, VDD = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER CONDITIONS MIN 69 TYP MAX UNITS Maximum Duty Cycle VOUT = 4.5V 75 % Minimum Duty Cycle VOUT = 4.5V 7.5 % COMP Transconductance VCOMP = 1.5V 55 μS 120 10 k Step-up off, FLED1/FLED2 on, supply current for each current source 0.6 mA Flash 750 Movie 125 COMP Discharge Resistance During shutdown or UVLO, from COMP to AGND OUT Discharge Resistance During shutdown or UVLO, from OUT to LX FLED1/FLED2 CURRENT REGULATOR IN Supply Current Maximum Current Setting 23.44mA setting Current Accuracy 492.24mA setting 750mA setting Current Regulator Dropout (Note 2) FLED1/FLED2 Leakage in Shutdown TA = +25°C -5 TA = +25°C -2.5 TA = -40°C to +85°C -4 TA = -40°C to +85°C -10 +20 ±0.5 +2.5 +4 +5 492.24mA setting 110 93.75mA setting VFLED1 = VFLED2 = 5.5V mA TA = +25°C -1 TA = +85°C 50 100 0.01 +1 0.1 % % % mV μA INDLED CURRENT REGULATOR IN Supply Current Step-up converter off, INDLED on 0.6 mA Maximum Current Setting 16 mA 0.5mA setting Current Accuracy Current Regulator Dropout INDLED Leakage in Shutdown 16mA setting TA = +25°C -10 TA = +25°C -3 TA = -40°C to +85°C -5 TA = +25°C -1 16mA setting (Note 2) VINDLED = 5.5V TA = +85°C +10 % +3 % +5 % 55 130 mV 0.01 +1 ±0.5 0.1 μA PROTECTION CIRCUITS NTC BIAS Current NTC Overtemperature Detection Threshold VNTC falling, 100mV hysteresis, NTC_CNTL[2:0] = 100 NTC Short Detection Threshold VNTC falling 19.4 20 20.6 μA 388 400 412 mV 100 Flash Duration Timer Range In 50ms steps (Note 3) Flash Duration Timer Accuracy (400ms Setting) TA = +25°C 360 50 TA = -40°C to +85°C 320 mV 800 400 440 480 ms ms Minimum Flash Duration FLASH_EN[2:0] = 1XX 2 ms Flash Safety Timer Reset Inhibit Period From falling edge of LED_EN until flash safety timer is reset 30 ms Watchdog Timer Range In 4s steps 4 4 _______________________________________________________________________________________ 16 s Adaptive Step-Up Converters with 1.5A Flash Driver (VIN = 3.6V, VAGND = VPGND = VFGND = 0V, VDD = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER MIN TYP MAX Watchdog Timer Accuracy (4s setting) TA = +25°C CONDITIONS 3.6 4 4.4 TA = -40°C to +85°C 3.2 Open LED Detection Threshold FLED1, FLED2, INDLED enabled 100 Shorted LED Detection Threshold FLED1, FLED2, INDLED enabled Open and Short Debounce Timer 4.8 From LED open or short detected until LED current regulator is disabled Thermal-Shutdown Hysteresis Thermal Shutdown UNITS s mV VOUT 1V V 30 ms 20 °C +160 °C MAXFLASH Low-Battery Detect Threshold Range 33mV steps 2.5 Low-Battery Voltage Threshold Accuracy ±2.5 Low-Battery Voltage Hysteresis Programmable Range 100 Low-Battery Voltage Hysteresis Step Size Low-Battery Reset Time 3.4 V % 200 100 mV mV LB_TMR[1:0] = 00 200 250 300 LB_TMR[1:0] = 01 400 500 600 μs Note 1: All devices are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design. Note 2: LED current regulator dropout voltage is defined as the voltage when current drops 10% from the current level measured at 0.6V. Note 3: Flash duration is from rising edge of LED_EN until IFLED = 0A (safety time in one-shot mode). Note 4: The adaptive output voltage regulation threshold is individually set on each device to 75mV above the dropout voltage of the LED current regulators. This ensures minimum power dissipation on the IC during a flash event. The dropout voltage chosen is the highest measured dropout voltage of FLED1, FLED2, and INDLED. _______________________________________________________________________________________ 5 MAX8834Y/MAX8834Z ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (Circuit of Figure 1, VIN = 3.6V, VOUT = 3.8V, VDD = 3.0V, TA = +25°C, unless otherwise noted.) VOUT = 3.8V IOUT = 750mA 60 VOUT = 5V IOUT = 250mA VOUT = 3.8V IOUT = 250mA 20 0 2.5 3.0 VOUT = 5V IOUT = 250mA 40 VOUT = 3.8V IOUT = 250mA 30 20 FOR VIN > VOUT, VOUT INCREASES ABOVE THE PROGRAMMED VALUE DUE TO THE MINIMUM DUTY CYCLE CONSTRAINT. 10 3.5 4.0 4.5 VOUT = 5V VOUT = 3.8V IOUT = 16mA IOUT = 16mA 0 5.0 2.5 3.0 3.5 4.0 4.5 MAX8834Y/Z toc03 VIN = 2.5V 60 40 20 FOR VIN > VOUT, VOUT INCREASES ABOVE THE PROGRAMMED VALUE DUE TO THE MINIMUM DUTY CYCLE CONSTRAINT. 10 VIN = 3.2V 0 1 5.0 10 100 1000 10,000 INPUT VOLTAGE (V) INPUT VOLTAGE (V) OUTPUT CURRENT (mA) STEP-UP CONVERTER EFFICIENCY vs. OUTPUT CURRENT (MAX8834Z) STEP-UP CONVERTER SUPPLY CURRENT vs. SUPPLY VOLTAGE STEP-UP CONVERTER SUPPLY CURRENT vs. TEMPERATURE 100 80 VIN = 3.2V 60 VIN = 2.5V 15 VOUT = 3.8V 12 SUPPLY CURRENT (mA) VIN = 3.6V 40 20 20 VOUT = 5V MAX8834Z 9 MAX8834Y 6 15 MAX8834Z 10 MAX8834Y 5 3 0 0 1 10 100 10,000 1000 2.5 3.0 OUTPUT CURRENT (mA) 3.5 4.0 4.5 5 IFLED1 = 492.19mA IFLED2 = 125mA 0 IFLED2 = 492.19mA IINDLED = 16mA IFLED1 = 750mA IFLED2 = 750mA 10 8 LED CURRENT ACCURACY (%) IFLED1 = 125mA IFLED2 = 125mA 6 IFLED1 = 125mA 4 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 IFLED1 = 492.19mA 0 IINDLED = 16mA -2 IFLED1 = 750mA -4 -6 IFLED2 = 492.19mA IFLED2 = 750mA VOUT = 5V -10 -10 3.5 35 2 -8 VOUT = 5V 3.0 10 TEMPERATURE (°C) LED CURRENT ACCURACY vs. TEMPERATURE MAX8834Y/Z toc07 LED CURRENT ACCURACY (%) 10 2.5 -15 SUPPLY VOLTAGE (V) LED CURRENT ACCURACY vs. INPUT VOLTAGE -5 -40 5.0 MAX8834Y/Z toc08 0 6 80 60 50 VIN = 3.6V MAX8834Y/Z toc06 30 VOUT = 5V IOUT = 750mA SUPPLY CURRENT (mA) 40 VOUT = 5V IOUT = 750mA 70 MAX8834Y/Z toc05 50 VOUT = 5V IOUT = 16mA VOUT = 3.8V IOUT = 750mA 80 EFFICIENCY (%) 70 90 MAX8834Y/Z toc04 EFFICIENCY (%) 80 100 MAX8834Y/Z toc02 VOUT = 3.8V IOUT = 16mA 100 MAX8834Y/Z toc01 100 90 STEP-UP CONVERTER EFFICIENCY vs. OUTPUT CURRENT (MAX8834Y) STEP-UP CONVERTER EFFICIENCY vs. INPUT VOLTAGE (MAX8834Z) EFFICIENCY (%) STEP-UP CONVERTER EFFICIENCY vs. INPUT VOLTAGE (MAX8834Y) EFFICIENCY (%) MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver -40 -15 10 35 60 TEMPERATURE (°C) _______________________________________________________________________________________ 85 60 85 Adaptive Step-Up Converters with 1.5A Flash Driver OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE 0.2 0 MAX8834Y, IOUT = 250mA -0.2 -0.4 MAX8834Z, IOUT = 250mA -0.6 MAX8834Y/Z toc10 MAX8834Y, NO LOAD 5 OSCILLATOR FREQUENCY (MHz) VOUT = 5V MAX8834Z, NO LOAD 0.4 MAX8834Y/Z toc09 OUTPUT VOLTAGE ACCURACY (%) 0.6 INTERNAL OSCILLATOR FREQUENCY vs. SUPPLY VOLTAGE MAX8834Z 4 3 2 MAX8834Y 1 0 -40 -15 10 35 60 85 2.5 3.0 3.5 4.0 4.5 5.0 TEMPERATURE (°C) SUPPLY VOLTAGE (V) STARTUP WAVEFORM (MAX8834Y, VOUT = 5V) STARTUP WAVEFORM (MAX8834Y, ADAPTIVE MODE) MAX8834Y/Z toc11 5V VOUT VLX MAX8834Y/Z toc12 2V/div VOUT 2V/div 2V/div VLX 2V/div VOUT = 5V ILED1 = 31.25mA ILX 5.5 ADAPTIVE MODE ILED1 = 31.25mA ILX 500mA/div 500mA/div VCOMP 1V/div 1V/div VCOMP 1ms/div 1ms/div STARTUP WAVEFORM (MAX8834Z, VOUT = 5V) STARTUP WAVEFORM (MAX8834Z, ADAPTIVE MODE) MAX8834Y/Z toc13 5V VOUT VLX MAX8834Y/Z toc14 2V/div VOUT 2V/div 2V/div VLX 2V/div VOUT = 5V ILED1 = 31.25mA ILX ADAPTIVE MODE ILED1 = 31.25mA ILX 500mA/div 500mA/div VCOMP 1V/div 1ms/div 1V/div VCOMP 1ms/div _______________________________________________________________________________________ 7 MAX8834Y/MAX8834Z Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 3.6V, VOUT = 3.8V, VDD = 3.0V, TA = +25°C, unless otherwise noted.) MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 3.6V, VOUT = 3.8V, VDD = 3.0V, TA = +25°C, unless otherwise noted.) SHUTDOWN WAVEFORM (MAX8834Y, VOUT = 5V) SHUTDOWN WAVEFORM (MAX8834Y, ADAPTIVE MODE) MAX8834Y/Z toc15 VOUT 5V VLX VOUT = 5V ILED1 = 31.25mA ILX MAX8834Y/Z toc16 2V/div VOUT 2V/div 2V/div VLX 2V/div 500mA/div 1V/div VCOMP ADAPTIVE MODE ILED1 = 31.25mA ILX VCOMP 1V/div 400μs/div 400μs/div SHUTDOWN WAVEFORM (MAX8834Z, VOUT = 5V) SHUTDOWN WAVEFORM (MAX8834Z, ADAPTIVE MODE) MAX8834Y/Z toc17 VOUT MAX8834Y/Z toc18 2V/div 5V 2V/div VLX VOUT = 5V ILED1 = 31.25mA ILX VCOMP 500mA/div 500mA/div 1V/div VOUT 2V/div VLX 2V/div ADAPTIVE MODE ILED1 = 31.25mA ILX 500mA/div VCOMP 1V/div 400μs/div 400μs/div LIGHT-LOAD SWITCHING WAVEFORMS (MAX8834Y) LIGHT-LOAD SWITCHING WAVEFORMS (MAX8834Z) MAX8834Y/Z toc20 MAX8834Y/Z toc19 2V/div VLX 2V/div VLX 0V 0mA 200mA/div ILX VOUT = 5V IOUT = 16mA VOUT AC RIPPLE 400ns/div 8 20mV/div 0V 0mA 200mA/div ILX VOUT = 5V IOUT = 16mA VOUT AC RIPPLE 20mV/div 400ns/div _______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver HEAVY-LOAD SWITCHING WAVEFORMS (MAX8834Y) HEAVY-LOAD SWITCHING WAVEFORMS (MAX8834Z) MAX8834Y/Z toc21 MAX8834Y/Z toc22 2V/div VLX 2V/div VLX 0V 0V 1.5A ILX 500mA/div VOUT = 5V IOUT = 1A VOUT AC RIPPLE 50mV/div 500mA/div 1.5A ILX VOUT = 5V IOUT = 1A VOUT AC RIPPLE 50mV/div 400ns/div 400ns/div GSMB WAVEFORM MAXFLASH FUNCTION MAX8834Y/Z toc23 VOUT = 5V ILIM = 500mA IFLED1 = IFLED2 = 515.63mA tHC_TRM = 80μs VGSMB IIN MAX8834Y/Z toc24 3.6V 2V/div VIN VIN DROPS BELOW THE THRESHOLD VOLTAGE 3.6V 200mV/div 1A/div VIN INCREASES TO THE THRESHOLD IFLED1 500mA/div IFLED1 IFLED2 200mV/div 1ms/div 10ms/div OUTPUT VOLTAGE LINE REGULATION (MAX8834Y) OUTPUT VOLTAGE LINE REGULATION (MAX8834Z) VOUT = 5V VOUT = 5V 5.01 OUTPUT VOLTAGE (V) 5.01 IOUT = 16mA 5.00 4.99 IOUT = 250mA MAX8834Y/Z toc26 5.02 MAX8834Y/Z toc25 5.02 OUTPUT VOLTAGE (V) 0mA 500mA/div VOUT = 5V IFLED1 = 750mA VLB_TH = 3.0V VLB_HYS DISABLED tTMR_DUR = 50ms IOUT = 16mA 5.00 4.99 IOUT = 250mA IOUT = 750mA IOUT = 750mA 4.98 4.98 4.97 4.97 2.5 3.0 3.5 INPUT VOLTAGE (V) 4.0 4.5 2.5 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) _______________________________________________________________________________________ 9 MAX8834Y/MAX8834Z Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 3.6V, VOUT = 3.8V, VDD = 3.0V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 3.6V, VOUT = 3.8V, VDD = 3.0V, TA = +25°C, unless otherwise noted.) OUTPUT VOLTAGE LOAD REGULATION (MAX8834Y) OUTPUT VOLTAGE LOAD REGULATION (MAX8834Z) 5.00 4.99 4.98 MAX8834Y/Z toc28 5.01 OUTPUT VOLTAGE (V) 5.01 4.97 5.00 4.99 4.98 4.97 VOUT = 5V VOUT = 5V 4.96 4.96 1 10 100 1000 10,000 1 10 100 1000 OUTPUT CURRENT (mA) INPUT CURRENT LIMIT vs. PROGRAMMED OUTPUT VOLTAGE INPUT CURRENT LIMIT vs. PROGRAMMED VALUE ILIM = 500mA 570 560 550 540 530 520 10,000 1000 VOUT = 5V INPUT CURRENT LIMIT (mA) 580 MAX8834Y/Z toc29 OUTPUT CURRENT (mA) MAX8834Y/Z toc30 OUTPUT VOLTAGE (V) 5.02 MAX8834Y/Z toc27 5.02 INPUT CURRENT LIMIT (mA) MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver 800 600 IDEAL LINE 400 200 510 0 500 3.7 4.0 4.3 4.6 4.9 PROGRAMMED OUTPUT VOLTAGE (V) 10 5.2 0 200 400 600 PROGRAMMED VALUE (mA) ______________________________________________________________________________________ 800 Adaptive Step-Up Converters with 1.5A Flash Driver PIN NAME FUNCTION A1, B1 OUT Regulator Output. Connect OUT to the anodes of the external LEDs. Bypass OUT to PGND with a 10μF ceramic capacitor. OUT is connected to LX through an internal 10k resistor during shutdown. A2, B2 LX Inductor Connection. Connect LX to the switched side of the inductor. LX is internally connected to the drains of the internal MOSFETs. LX is connected to OUT through an internal 10k resistor during shutdown. A3, B3 PGND Power Ground. Connect PGND to AGND and to the input capacitor ground. Connect PGND to the PCB ground plane. A4 IN Analog Supply Voltage Input. The input voltage range is 2.5V to 5.5V. Bypass IN to AGND and PGND with a 10μF ceramic capacitor as close as possible to the IC. IN is high impedance during shutdown. A5 VDD Logic Input Supply Voltage. Connect VDD to the logic supply driving SCL, SDA, LED_EN, and GSMB. Bypass VDD to AGND with a 0.1μF ceramic capacitor. When VDD is below the UVLO, the I2C registers reset and the step-up converter turns off. B4 SCL I2C Clock Input. Data is read on the rising edge of SCL. B5 AGND Analog Ground. Connect AGND to PGND and to the input capacitor ground. Connect AGND to the PCB ground plane. C1 COMP Compensation Input. See the Compensation Network Selection section for details. COMP is internally pulled to AGND through a 180 resistor in shutdown. C2, D2 FGND FLED1/FLED2 and INDLED Power Ground. Connect FGND to PGND. C3 LED_EN LED Enable Logic Input. LED_EN controls FLED1, FLED2, and INDLED, depending on control bits written into the LED_CNTL register. See the LED_EN Control register description for an explanation of this input function. LED_EN has an internal 800k pulldown resistor to AGND. C4 GSMB GSM Blank Signal. Assert GSMB to reduce the current regulator settings according to the values programmed into the GSMB_CUR register. The status of the flash safety timer and the flash/movie mode values in the current regulator registers are not affected by the GSMB state. Connect GSMB to the PA module enable signal or other suitable logic signal that indicates a GSM transmit is in process. Polarity of this signal is set by a bit in the GSMB_CUR register (default is active-high). GSMB has an internal 800k pulldown resistor to AGND. C5 SDA I2C Data Input. Data is read on the rising edge of SCL and data is clocked out on the falling edge of SCL. D1 FLED2 FLED2 Current Regulator. Current flowing into FLED2 is based on the internal I2C registers FLASH2_CUR and MOVIE_CUR. Connect FLED2 to the cathode of an external flash LED or LED module. FLED2 is high impedance during shutdown. If unused, connect FLED2 to ground. D3 FLED1 FLED1 Current Regulator. Current flowing into FLED1 is based on the internal I2C registers FLASH1_CUR and MOVIE_CUR. Connect FLED1 to the cathode of an external flash LED or LED module. FLED1 is high impedance during shutdown. If unused, connect FLED1 to ground. D4 INDLED D5 NTC INDLED Current Regulator. Current flowing into INDLED is based on the internal I2C registers IND_CUR. Connect INDLED to the cathode of an external indicator LED. INDLED is high impedance during shutdown. If unused, connect INDLED to ground. NTC Bias Output. NTC provides 20μA to bias the NTC thermistor. The NTC voltage is compared to the trip threshold programmed by the NTC_CNTL register. NTC is high impedance during shutdown. Connect NTC to IN if not used. See the Finger-Burn Protection (NTC) section for details. ______________________________________________________________________________________ 11 MAX8834Y/MAX8834Z Pin Description MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Detailed Description The MAX8834Y/MAX8834Z flash drivers integrate an adaptive 1.5A PWM step-up DC-DC converter, two 750mA white LED camera flash/movie current regulators, and a 16mA indicator LED current regulator. An I2C interface controls individual output on/off, the stepup output voltage setting, the movie/flash current, and the flash timer duration settings. Step-Up Converter (LX, OUT, COMP, PGND) The MAX8834Y/MAX8834Z include a fixed-frequency, PWM step-up converter that supplies power to the flash LEDs. The output voltage is programmable from 3.7V to 5.2V (in 100mV steps) through the I2C interface. The output voltage can also be set adaptively based on the LED forward voltage. The step-up converter switches an internal power MOSFET and synchronous rectifier at a constant 2MHz or 4MHz frequency, with varying duty cycle up to 75%, to maintain constant output voltage as the input voltage and load vary. Internal circuitry prevents any unwanted subharmonic switching by forcing a minimum 7% (typ) duty cycle. When the step-up converter is set to dropout mode, the internal synchronous rectifier is driven fully on, keeping the voltage at OUT equal to the LX input. This mode provides the lowest current consumption when driving LEDs with low forward voltage. The output voltage is internally monitored for a fault condition. If the output voltage drops below 8% (typ) of the nominal programmed value, a POK fault is indicated in STATUS1 register bit 5. This feature is disabled if the step-up converter is set to operate in adaptive mode. Overvoltage Protection The MAX8834Y/MAX8834Z include a comparator to monitor the output voltage (V OUT ) during adaptive mode operation of the step-up converter. If at anytime the output voltage exceeds a maximum threshold of 5.5V, the COMP capacitor is discharged until the output voltage is reduced by the 200mV (typ) hysteresis. Once the output voltage drops below this threshold, normal charging of the COMP capacitor is resumed. Flash Current Regulator (FLED1 and FLED2) A low-dropout linear current regulator from FLED1/ FLED2 to FGND sinks current from the cathode terminal of the flash LED(s). The FLED1/FLED2 current is regulated to I2C programmable levels for movie mode (up to 125mA, see Table 5) and flash mode (up to 750mA, 12 see Tables 3 and 4). The movie mode provides continuous lighting when enabled through I 2C or LED_EN. When the flash mode is enabled, a flash safety timer, programmable from 50ms to 800ms through I2C, limits the duration of the flash mode. Once the flash safety timer expires, the current regulators return to movie mode if movie mode was active when a flash event was triggered. The flash mode has priority over the movie mode. Flash Safety Timer The flash safety timer is activated any time flash mode is selected, either with LED_EN or through the I2C interface. The flash safety timer, programmable from 50ms to 800ms through I2C, limits the duration of the flash mode in case LED_EN is stuck high or the I2C command to turn off has not been sent within the programmed flash safety timer duration. This timer can be configured to operate either in one-shot mode or maximum flash duration mode (see Table 9). In one-shot mode, the flash function is initiated on the rising edge of LED_EN (or I2C bit) and terminated based on the programmed value of the safety timer (see Figure 1). In the maximum flash timer mode, flash function remains enabled as long as LED_EN (or I2C bit) is high, unless the preprogrammed safety timer times out (see Figure 2). Once the flash mode is disabled, by either LED_EN, I2C, or flash safety timer, the flash has to be off for a minimum time (flash safety timer reset inhibit period), before it can be reinitiated (see Figure 3). This prevents spurious events from re-enabling the flash mode. Indicator Current Regulator (INDLED) A low-dropout linear current regulator from INDLED to FGND sinks current from the cathode terminal of the indicator LED. The INDLED current is regulated to I2C programmable levels up to 16mA. Programmable control is provided for ramp-up (OFF to ON) and rampdown (ON to OFF) times, as well as blink rate and duty cycle. The user can choose to enable or disable the ramp time and blink rate features. See Tables 6, 7, and 8 for more information. INDLED Blink Function INDLED current regulator is able to generate a blink function. The OFF and ON time for INDLED are set using the I2C interface. See Figure 4. INDLED Ramp Function The INDLED current regulator output provides ramp-up/ down for smooth transition between different brightness settings. The ramp-up/down times are controlled by the ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z ENABLING OF FLASH MODE BY LED_EN OR I2C CONTROL ONE-SHOT FLASH TIMER ONE-SHOT FLASH TIMER Figure 1. One-Shot Flash-Timer Mode ENABLING OF FLASH MODE BY LED_EN OR I2C CONTROL MAXIMUM FLASH SAFETY TIMER MAXIMUM FLASH TIMER Figure 2. Maximum Flash-Timer Mode ENABLING OF FLASH MODE BY LED_EN OR I2C CONTROL 30ms Figure 3. Flash Safety Timer Reset Inhibit Period IIND[4:0] tIND_OFF tIND_ON Figure 4. Blink Function Timing IND_RU and IND_RD control bits, and the ramp function is enabled/disabled by the IND_RP_EN bit. The current regulator increases/decreases the current onestep every tRAMP/32 until 0mA or IND[4:0] current is reached. See Figures 5 and 6. Combining BLINK Timer and Ramp Function When using the ramp function for INDLED together with the blink timer, keep the ramp-up timer shorter than the ON blink timer and the ramp-down timer shorter than the OFF timer. Failing to comply with this results in the ______________________________________________________________________________________ 13 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver 128ms IINDLED = FULL SCALE 256ms 512ms 1024ms IINDLED = 1/2 SCALE 0mA Figure 5. Ramp-Up Behavior IINDLED = FULL SCALE IINDLED = 1/2 SCALE 0mA 128ms 256ms 512ms 1024ms Figure 6. 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 = OFF t= tIND_RU 32 t= tIND_RD 32 Figure 7. Combining RAMP Function and Blink Timer programmed current not being reached during the ON time, or the INDLED current not returning to 0mA during the OFF time. See Figure 7. tIND _ ON ≥ tIND _ RU tIND _ OFF ≥ 32 (IND _ LED + 1) tIND _ RD 32 (IND _ LED + 1) where IND_LED is the code from 0 to 31 specified in the IND_LED[4:0]. LED Enable Input (LED_EN) The LED_EN logic input can enable/disable the FLED1, FLED2, and INDLED current regulators. It can be programmed to control movie mode, flash mode, and indicator mode by using the IND_EN, MOVIE_EN, and FLASH_EN bits, respectively. See Table 8 for more information. 14 If FLED1/FLED2 is enabled for both movie and flash modes at the same time, flash mode has priority. Once the safety timer expires, the current regulator then returns to the movie mode. Watchdog Timer The MAX8834Y/MAX8834Z include a watchdog timer function that can be programmed using the I2C interface from 4 seconds to 16 seconds with a 4-second step. If the watchdog timer expires, the MAX8834Y/ MAX8834Z interpret it as an indication that the system is no longer responding and enters safe mode. In safe mode, the MAX8834Y/MAX8834Z disable all current regulators and the step-up DC-DC converter to prevent potential damage to the system. The I2C setting for the respective registers does not change, therefore, resetting the watchdog timer reverts the MAX8834Y/ MAX8834Z back to the state present before entering safe mode. ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver WATCHDOG TIMER RESET WATCHDOG TIMER RESET MAX8834Y/MAX8834Z WATCHDOG TIMER ENABLED WATCHDOG TIMEOUT SUSPENDING ALL CURRENT REGULATIONS WATCHDOG TIMER RESET WDT_RST IS CLEARED (I2C) WDT_EN (I2C) WDT_RST WATCHDOG TIMER LED_EN IFLED_ OR IINDLED t < WDT_DUR[1:0] t < WDT_DUR[1:0] t < WDT_DUR[1:0] t > WDT_DUR[1:0] Figure 8. Watchdog Timer Timing Diagram 1 WATCHDOG TIMER ENABLED WATCHDOG TIMER RESET WATCHDOG TIMEOUT SUSPENDING ALL CURRENT REGULATIONS WATCHDOG TIMER RESET WATCHDOG TIMER RESET WDT_RST IS CLEARED (I2C) WDT_EN (I2C) WDT_RST WATCHDOG TIMER LED_EN IFLED_ OR IINDLED t < WDT_DUR[1:0] t < WDT_DUR[1:0] t > WDT_DUR[1:0] t < WDT_DUR[1:0] Figure 9. Watchdog Timer Timing Diagram 2 Setting the WDT_EN bit to 1 in the TMR_DUR register (Table 9) enables the watchdog timer. Resetting the watchdog timer is achieved by the rising or falling edge of LED_EN or by setting bit 0 in the WDT_RST register (Table 14). See Figures 8 and 9 for two examples of watchdog timer timing diagrams. ______________________________________________________________________________________ 15 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver GSMB EVENT GSMB (ACTIVE-HIGH) INPUT CURRENT PREDEFINED INPUT CURRENT LIMIT DURING GSMB FLED1/FLED2 DECREASED ONE LSB SINCE IIN > ILIM[3:0] FLED1/FLED2 INCREASED ONE LSB SINCE IIN < ILIM[3:0] FLED2 OUTPUT CURRENT FLED1 OUTPUT CURRENT FLASH1_CUR SETTING TIME HC_TMR[1:0] 1μs AFTER GSMB ACTIVATED, FLED_ GOES TO THE MINIMUM SETTING 1μs AFTER GSMB DEACTIVATED, FLED_ GOES TO THE PREVIOUS SETTING Figure 10. Input Current Limit During GSMB Event GSM Blank Function (GSMB) The GSMB input is provided to allow the flash current to be momentarily reduced during a GSM transmit to reduce the peak current drawn from the battery. The input current limit ensures that the maximum possible output current is always provided, regardless of the input voltage and the LED forward voltages. When a GSMB event is triggered, the FLED1 and FLED2 current regulators go to the lowest setting to ensure the current drawn from the battery is quickly reduced to a safe level. The MAX8834Y/MAX8834Z 16 then start increasing the FLED1 and FLED2 current by one LSB steps, at a time interval set by HC_TMR[1:0] (see Table 11). The increasing continues until either the predefined FLED1/FLED2 current setting is reached or the input current exceeds the maximum predefined input current limit during a GSMB event. When the input current exceeds the predefined input current limit, the FLED1/FLED2 current is reduced by one LSB. The MAX8834Y/MAX8834Z continue to adjust the FLED1 and FLED2 up and down depending on the input current limit as long as the GSMB event is present. See Figure 10 for more detailed information. ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver Finger-Burn Protection (NTC) An NTC input is provided for the (optional) finger-burn protection feature. To use this feature, connect a 100kΩ NTC with B = 4550 between NTC and AGND. NTC sources 20µA current and the voltage established by this current and the NTC resistance is compared internally to a voltage threshold in the range of 200mV to 550mV, programmed through bits [2:0] of the NTC Control register (see Table 10). If the voltage on the NTC pin falls below the programmed threshold during a flash event, the flash cycle is immediately terminated, and an indication is latched through bit 3 in the STATUS1 register (see Table 15). To disable this function, clear bit 3 (enable bit) in the NTC Control register. MAXFLASH Function During high load currents, the battery voltage momentarily drops due to its internal ESR, together with the serial impedance from the battery to the load. For equipment requiring a minimum voltage for stable operation, the battery ESR needs to be calculated to estimate the maximum battery current that maintains the battery voltage above the critical threshold. Due to the complicated measurement of the battery ESR, the MAX8834Y/MAX8834Z feature the MAXFLASH function to prevent the battery voltage from dropping below the threshold voltage. See Figure 11 for details. The MAX8834Y/MAX8834Z input voltage is monitored during a FLASH/MOVIE event. If the input voltage drops below a predefined threshold (VLB_TH), it indicates that the FLASH/MOVIE event is drawing more current than the battery can support. As a result, the FLED1/FLED2 current regulators start decreasing their output currents by one step. Therefore, the input current is reduced and the input voltage starts to rise due to the internal battery ESR. The input voltage is then sampled again after tLB_TMR and compared to VLB_TH plus a predefined hysteresis (V LB_HYS ). If it is still below VLB_TH + VLB_HYS, the FLED1/FLED2 current regulators reduce their output current again to ensure that minimum input voltage is available for the system. If the input voltage is above VLB_TH + VLB_HYS, the current regulator increases the output current by one step (if it is less than the user-defined output current). To disable the hysteresis, set LB_HYS[1:0] to 11. In this case, after the FLED1/FLED2 current is reduced, it stays at the current setting. Figures 12, 13, and 14 show examples of MAXFLASH function operation. See Tables 12 and 13 for control register details. The MAXFLASH function continues for the entire duration of the FLASH/MOVIE event to ensure that the FLASH/MOVIE output current is always maximized for the specific operating conditions. Undervoltage Lockout The MAX8834Y/MAX8834Z contain undervoltage lockout (UVLO) circuitry that disables the IC until VIN is greater than 2.3V (typ). Once V IN rises above 2.3V (typ), the UVLO circuitry does not disable the IC until VIN falls below the UVLO threshold minus the hysteresis voltage. The MAX8834Y/MAX8834Z also contain a VDD UVLO circuitry that monitors the VDD voltage. When the VDD voltage falls below 1.4V (typ), the contents of all the logic registers are reset to their default states. The logic registers are only reset in a VDD UVLO condition and not an IN UVLO condition. tLB_TMR IN IOUT_MAX DOWN VLB_TH CURRENT REGULATOR UP VLB_HYS VLB_TH Figure 11. Block Diagram of MAXFLASH Function ______________________________________________________________________________________ 17 MAX8834Y/MAX8834Z To use this feature, connect the logic signal used to enable the PA, or equivalent, to the GSMB input. Assertion of this signal does not change the current status of the flash safety timer or the flash current values stored in the I2C registers. Once the signal is deasserted, the current regulators change back to their previously programmed values. Polarity of this signal is controlled through bit 6 in the GSMB_CUR register (Table 11). The default is active-high. FLASH/MOVIE CURRENT BATTERY VOLTAGE VLB_TH + VLB_HYS VLB_TH tLB_TMR TIME Figure 12. Example 1 of MAXFLASH Function Operation VLB_TH IMAX FLASH/MOVIE CURRENT VLB_TH + VLB_HYS BATTERY VOLTAGE REDUCTION IN BATTERY CURRENT CAUSED BY OTHER SYSTEM tLB_TMR TIME Figure 13. Example 2 of MAXFLASH Function Operation VLB_TH + VLB_HYS VLB_TH FLASH CURRENT IS NOT INCREASED AGAIN SINCE LB_HYS = 11 IMAX tLB_TMR TIME Figure 14. Example 3 of MAXFLASH Function Operation with Hysteresis Disabled 18 ______________________________________________________________________________________ FLASH/MOVIE CURRENT REDUCTION IN BATTERY CURRENT CAUSED BY OTHER SYSTEM BATTERY VOLTAGE MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Adaptive Step-Up Converters with 1.5A Flash Driver Open/Short Detection The MAX8834Y/MAX8834Z monitor the FLED1, FLED2, and INDLED voltage to detect any open or short LEDs. A short fault is detected when the voltage rises above VOUT - 1V (typ), and an open fault is detected when the voltage falls below 100mV. The fault detection circuitry is only activated when the corresponding current regulator is enabled and provides a continuous monitor of the current regulator condition. Once a fault is detected, the corresponding current regulator is disabled and the status is latched into the corresponding fault register bit (see Table 15). This allows the processor to determine the MAX8834Y/MAX8834Z operating condition. Shutdown and Standby The MAX8834Y/MAX8834Z are in shutdown when either VIN or VDD are in UVLO. In shutdown, supply current is reduced to 0.1µA (typ). When VIN is above its UVLO threshold, but VDD is below its UVLO threshold, the IC disables its internal reference, keeps all registers reset, turns the step-up converter off, and turns the FLED1/FLED2 current regulators off (high impedance). Once a logic-level voltage is supplied to VDD, the IC enters standby condition and is ready to accept I2C commands. The internal MOSFET, synchronous rectifier, and FLED1/FLED2 are also high impedance in standby. Thermal Shutdown Thermal shutdown limits total power dissipation in the MAX8834Y/MAX8834Z. When the junction temperature exceeds +160°C (typ), the IC turns off, allowing itself to cool. The IC turns on and begins soft-start after the junction temperature cools by 20°C. This results in a pulsed output during continuous thermal overload conditions. I2C Serial Interface An I2C-compatible, 2-wire serial interface controls the step-up converter output voltage, flash, movie, and indicator current settings, flash duration, and other parameters. The serial bus consists of a bidirectional serial-data line (SDA) and a serial-clock input (SCL). The MAX8834Y/MAX8834Z are slave-only devices, relying upon a master to generate a clock signal. The master initiates data transfer to and from the MAX8834Y/ Typical shutdown timing characteristics are shown in the Typical Operating Characteristics. Parallel Connection of Current Regulators The FLED1/FLED2 current regulators can be connected in parallel as long as the system software properly sets the current levels for each regulator. Unused current regulators may be connected to ground. The FLED1/ SDA tSU,STA tSU,DAT tLOW tBUF tHD,STA tSU,STO tHD,DAT tHIGH SCL tHD,STA tR tF START CONDITION REPEATED START CONDITION STOP CONDITION START CONDITION Figure 15. 2-Wire Serial Interface Timing Detail ______________________________________________________________________________________ 19 MAX8834Y/MAX8834Z FLED2 regulators must be disabled through I 2 C to avoid a fault detection from an open or short. Soft-Start The step-up converter implements a soft-start to control inrush current when it turns on. It soft-starts by charging CCOMP with a 100µA current source. During this time, the internal MOSFET is switching at the minimum duty cycle. Once V COMP rises above 1V, the duty cycle increases until the output voltage reaches the desired regulation level. COMP is pulled to AGND with a 180Ω (typ) internal resistor during IN, UVLO, dropout mode, or shutdown. See the Typical Operating Characteristics for an example of soft-start operation. Soft-start is reinitiated after UVLO or if the step-up converter is reenabled after shutdown or dropout mode. MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver SCL SDA START CONDITION (S) DATA LINE STABLE DATA VALID DATA ALLOWED TO CHANGE STOP CONDITION (P) Figure 16. Bit Transfer MAX8834Z and generates SCL to synchronize the data transfer (Figure 15). I2C is an open-drain bus. Both SDA and SCL are bidirectional lines, connected to a positive supply voltage through a pullup resistor. They both have Schmitt triggers and filter circuits to suppress noise spikes on the bus to assure proper device operation. A bus master initiates communication with the MAX8834Y/MAX8834Z as a slave device by issuing a START (S) condition followed by the MAX8834Y/ MAX8834Z address. The MAX8834Y/MAX8834Z address byte consists of 7 address bits and a read/ write bit (R/W). After receiving the proper address, the MAX8834Y/MAX8834Z issue an acknowledge bit by pulling SDA low during the ninth clock cycle. Slave Address The MAX8834Y/MAX8834Z act as a slave transmitter/ receiver. Its slave address is 0x94 for write operations and 0x95 for read operations. Bit Transfer Each data bit, from the most significant bit to the least significant bit, is transferred one by one during each clock cycle. During data transfer, the SDA signal is allowed to change only during the low period of the SCL clock and it must remain stable during the high period of the SCL clock (Figure 16). 20 START and STOP Conditions Both SCL and SDA remain high when the bus is not busy. The master signals the beginning of a transmission with a START (S) condition by transitioning SDA from high to low while SCL is high. When the master has finished communicating with the MAX8834Y/ MAX8834Z, it issues a STOP (P) condition by transitioning SDA from low to high while SCL is high. The bus is then free for another transmission (Figure 17). Both START and STOP conditions are generated by the bus master. Acknowledge The acknowledge bit is used by the recipient to handshake the receipt of each byte of data (Figure 18). After data transfer, the master generates the acknowledge clock pulse and the recipient pulls down the SDA line during this acknowledge clock pulse so the SDA line stays low during the high duration of the clock pulse. When the master transmits the data to the MAX8834Y/MAX8834Z, it releases the SDA line and the MAX8834Y/MAX8834Z take control of the SDA line and generate the acknowledge bit. When SDA remains high during this 9th clock pulse, this is defined as the not acknowledge signal. The master can then generate either a STOP condition to abort the transfer, or a repeated START condition to start a new transfer. ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver D7 D6 D0 SDA NOT ACKNOWLEDGE SDA BY SLAVE ACKNOWLEDGE SCL SCL 1 START CONDITION STOP CONDITION START CONDITION 2 8 9 CLOCK PULSE FOR ACKNOWLEDGEMENT Figure 17. START and STOP Conditions Figure 18. Acknowledge Write Operations The MAX8834Y/MAX8834Z recognize the write byte protocol as defined in the SMBus™ specification and shown in section A of Figure 19. The write byte protocol allows the I2C master device to send 1 byte of data to the slave device. The write-byte protocol requires a register pointer address for the subsequent write. The MAX8834Y/MAX8834Z acknowledge any register pointer even though only a subset of those registers actually exists in the device. The write byte protocol is as follows: 1) The master sends a start command. Use the following procedure to write to a sequential block of registers: 1) The master sends a start command. 2) The master sends the 7-bit slave address followed by a write bit. 2) The master sends the 7-bit slave address followed by a write bit. 3) The addressed slave asserts an acknowledge by pulling SDA low. 4) The master sends the 8-bit register pointer of the first register to write. 5) The slave acknowledges the register pointer. 6) The master sends a data byte. 7) The slave updates with the new data. 3) The addressed slave asserts an acknowledge by pulling SDA low. 4) The master sends an 8-bit register pointer. 5) The slave acknowledges the register pointer. 6) The master sends a data byte. 8) The slave acknowledges the data byte. 9) Steps 6 to 8 are repeated for as many registers in the block, with the register pointer automatically incremented each time. 10) The master sends a STOP condition. 7) The slave updates with the new data. 8) The slave acknowledges the data byte. 9) The master sends a STOP (P) condition. In addition to the write-byte protocol, the MAX8834Y/ MAX8834Z can write to multiple registers as shown in section B of Figure 19. This protocol allows the I2C master device to address the slave only once and then send data to a sequential block of registers starting at the specified register pointer. Read Operations The method for reading a single register (byte) is shown in section A of Figure 20. To read a single register: 1) The master sends a start command. 2) The master sends the 7-bit slave address followed by a write bit. 3) The addressed slave asserts an acknowledge by pulling SDA low. 4) The master sends an 8-bit register pointer. SMBus is a trademark of Intel Corp. ______________________________________________________________________________________ 21 MAX8834Y/MAX8834Z SDA BY MASTER MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver LEGEND MASTER TO SLAVE SLAVE TO MASTER A. WRITING TO A SINGLE REGISTER WITH THE WRITE BYTE PROTOCOL 1 S 7 SLAVE ADDRESS 1 1 8 1 8 1 1 NUMBER OF BITS 0 A REGISTER POINTER A DATA A P 8 1 8 1 A DATA X+1 A R/W B. WRITING TO MULTIPLE REGISTERS 1 7 1 1 8 1 S SLAVE ADDRESS 0 A REGISTER POINTER X A 8 1 8 DATA X+n-1 A DATA X+n DATA X NUMBER OF BITS ... R/W ... 1 NUMBER OF BITS A P Figure 19. Writing to the MAX8834Y/MAX8834Z 5) The slave acknowledges the register pointer. 6) The master sends a REPEATED START (Sr) condition. 7) The master sends the 7-bit slave address followed by a read bit. 8) The slave asserts an acknowledge by pulling SDA low. 9) The slave sends the 8-bit data (contents of the register). 10) The master asserts an acknowledge by pulling SDA low. 11) The master sends a STOP (P) condition. In addition, the MAX8834Y/MAX8834Z can read a block of multiple sequential registers as shown in section B of Figure 20. Use the following procedure to read a sequential block of registers: 1) The master sends a start command. 2) The master sends the 7-bit slave address followed by a write bit. 22 3) The addressed slave asserts an acknowledge by pulling SDA low. 4) The master sends an 8-bit register pointer of the first register in the block. 5) The slave acknowledges the register pointer. 6) The master sends a REPEATED START condition. 7) The master sends the 7-bit slave address followed by a read bit. 8) The slave asserts an acknowledge by pulling SDA low. 9) The slave sends the 8-bit data (contents of the register). 10) The master asserts an acknowledge by pulling SDA low. 11) Steps 9 and 10 are repeated for as many registers in the block, with the register pointer automatically incremented each time. 12) The master sends a STOP condition. ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver MASTER TO SLAVE SLAVE TO MASTER A. READING A SINGLE REGISTER 1 S 7 SLAVE ADDRESS 1 1 8 1 0 A REGISTER POINTER 1 1 8 1 A Sr 8 1 1 8 1 1 SLAVE ADDRESS 1 A DATA A P NUMBER OF BITS R/W B. READING MULTIPLE REGISTERS 1 S 7 SLAVE ADDRESS 0 1 REGISTER POINTER X A A 1 8 Sr 1 SLAVE ADDRESS R/W 8 DATA X+1 A NUMBER OF BITS 1 A ... R/W 8 ... 1 1 DATA X+1 1 A ... 8 DATA X+n-1 1 8 A DATA X+n 1 1 NUMBER OF BITS A P Figure 20. Reading from the MAX8834Y/MAX8834Z ______________________________________________________________________________________ 23 MAX8834Y/MAX8834Z LEGEND MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 1. Register Map TABLE REGISTER ADDRESS (hex) TYPE BOOST_CNTL Table 2 00 R/W Step-up converter control FLASH1_CUR Table 3 01 R/W FLED1 flash current control FLASH2_CUR Table 4 02 R/W FLED2 flash current control MOVIE_CUR Table 5 03 R/W FLED1 and FLED2 movie current control — 04 R/W Reserved for future use Table 6 05 R/W Indicator LED current control NAME Reserved for future use IND_CUR Reserved for future use DESCRIPTION — 06 R/W Reserved for future use Table 7 07 R/W Indicator LED ramp and blink control — 08 R/W Reserved for future use LED_CNTL Table 8 09 R/W FLED1, FLED2, and INDLED on/off and mode control, and definition of LED_EN logic input function TMR_DUR Table 9 0A R/W Watchdog timer and flash safety timer control NTC_CNTL Table 10 0B R/W NTC function control GSMB_CUR Table 11 0C R/W FLED1 and FLED2 current control during GSM transmit MAXFLASH1 Table 12 0D R/W MAXFLASH function register 1 MAXFLASH2 Table 13 0E R/W MAXFLASH function register 2 WDT_RST Table 14 16 R/W Watchdog timer reset STATUS1 Table 15 17 R STATUS2 Table 16 18 R — 19 R/W CHIP_ID1 Table 17 1A R Die type information CHIP_ID2 Table 18 1B R Die type and mask revision information IND_CNTL Reserved for future use Reserved for future use 24 Status register Status register Reserved for future use ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver This register contains step-up converter control values. REGISTER NAME BOOST_CNTL Address 0x00 Reset Value 0x00 Type Read/write Special Features — BIT NAME B7 (MSB) — Reserved for future use 0 B6 BOOST_EN 0 = Step-up converter off 1 = Step-up converter on 0 00 = Step-up voltage set adaptively 01 = Step-up voltage set programmatically according to BOOST_CNTL[3:0] 10 = Step-up converter runs in dropout 11 = Step-up converter automatically changes between adaptive regulation and dropout mode depending on operating conditions 00 B5 BOOST_MODE B4 B3 B2 BOOST_CNTL[3:0] B1 B0 (LSB) DESCRIPTION 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 DEFAULT VALUE 0000 ______________________________________________________________________________________ 25 MAX8834Y/MAX8834Z Table 2. BOOST_CNTL MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 3. FLASH1_CUR This register contains FLED1 flash current control values. REGISTER NAME FLASH1_CUR Address 0x01 Reset Value 0x00 Type Read/write Special Features BIT — NAME B7 (MSB) B6 B5 FLASH1[4:0] B4 B3 26 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 DEFAULT VALUE 00000 B2 — Reserved for future use B1 — Reserved for future use — B0 (LSB) — Reserved for future use — ______________________________________________________________________________________ — Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z Table 4. FLASH2_CUR This register contains FLED2 flash current control values. REGISTER NAME FLASH2_CUR Address 0x02 Reset Value 0x00 Type Read/write Special Features BIT — NAME B7 (MSB) B6 B5 FLASH2[4:0] B4 B3 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 DEFAULT VALUE 00000 B2 — Reserved for future use B1 — Reserved for future use — — B0 (LSB) — Reserved for future use — ______________________________________________________________________________________ 27 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 5. MOVIE_CUR This register contains FLED1 and FLED2 movie current control values. REGISTER NAME MOVIE_CUR Address 0x03 Reset Value 0x00 Type Read/write Special Features — BIT NAME B7 (MSB) — B6 B5 MOVIE1[2:0] B4 B3 — B2 B1 B0 (LSB) 28 MOVIE2[2:0] DESCRIPTION Reserved for future use FLED1 Movie Mode Current Setting 000 = 15.625mA 001 = 31.250mA 010 = 49.875mA 011 = 62.500mA 100 = 78.125mA 101 = 93.750mA 110 = 109.375mA 111 = 125.000mA Reserved for future use FLED2 Movie Mode Current Setting 000 = 15.625mA 001 = 31.250mA 010 = 49.875mA 011 = 62.500mA 100 = 78.125mA 101 = 93.750mA 110 = 109.375mA 111 = 125.000mA ______________________________________________________________________________________ DEFAULT NAME — 000 — 000 Adaptive Step-Up Converters with 1.5A Flash Driver This register contains indicator LED current control values. REGISTER NAME Address IND_CUR 0x05 Reset Value 0x00 Type Read/write Special Features — BIT NAME B7 (MSB) — DESCRIPTION 0 0 0 B6 IND_BL_EN INDLED Indicator Blink Timer Enable 0 = Indicator blink is disabled 1 = Indicator blink is enabled B5 IND_RP_EN INDLED Indicator Ramp-Up/Down Enable 0 = Indicator ramp-up/down is disabled 1= Indicator ramp-up/down is enabled B4 B3 B2 B1 B0 (LSB) IND[4:0] DEFAULT VALUE Reserved for future use 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 00000 ______________________________________________________________________________________ 29 MAX8834Y/MAX8834Z Table 6. IND_CUR MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 7. IND_CNTL This register contains indicator LED ramp and blink timer control. REGISTER NAME IND_CNTL Address 0x07 Reset Value 0x00 Type Read/write Special Features BIT — NAME IND_OFF 00 IND_ON INDLED Indicator On Blink Timer Control 00 = 128ms 01 = 256ms 10 = 512ms 11 = 1024ms 00 IND_RU[1:0] INDLED Indicator Ramp-Up Timer Control 00 = 128ms 01 = 256ms 10 = 512ms 11 = 1024ms 00 IND_RD[1:0] INDLED Indicator Ramp-Down Timer Control 00 = 128ms 01 = 256ms 10 = 512ms 11 = 1024ms 00 B6 B5 B4 B3 B2 B1 30 DEFAULT VALUE INDLED Indicator Off Blink Timer Control 00 = 512ms 01 = 1024ms 10 = 2048ms 11 = 4096ms B7 (MSB) B0 (LSB) DESCRIPTION ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver This register contains FLED1, FLED2 and INDLED on/off and mode control. REGISTER NAME LED_CNTL Address 0x09 Reset Value 0x00 Type Read/write Special Features BIT — NAME B7 (MSB) B6 IND_EN[1:0] B5 B4 MOVIE_EN[2:0] B3 B2 B1 B0 (LSB) FLASH_EN[2:0] DESCRIPTION INDLED Indicator Current Regulator Enable 00 = INDLED indicator LED is disabled 01 = INDLED indicator LED is disabled 10 = INDLED indicator LED is enabled 11 = INDLED indicator LED is controlled by LED_EN input FLED1/FLED2 MOVIE Mode Current Regulator Enable 000 = FLED1 and FLED2 movie mode disabled 001 = FLED1 movie mode is enabled, FLED2 movie mode is disabled 010 = FLED2 movie mode is enabled, FLED1 movie mode is disabled 011 = FLED1 and FLED2 movie mode is enabled 101 = FLED1 movie mode is controlled by LED_EN, FLED2 movie mode is disabled 110 = FLED2 movie mode is controlled by LED_EN, FLED1 movie mode is disabled 111 = FLED1 and FLED2 movie mode is controlled by LED_EN FLED1/FLED2 Flash Mode Current Regulator Enable 000 = FLED1 and FLED2 flash mode disabled 001 = FLED1 flash mode is enabled, FLED2 flash mode is disabled 010 = FLED2 flash mode is enabled, FLED1 flash mode is disabled 011 = FLED1 and FLED2 flash mode is enabled 101 = FLED1 flash mode is controlled by LED_EN, FLED2 flash mode is disabled 110 = FLED2 flash mode is controlled by LED_EN, FLED1 flash mode is disabled 111 = FLED1 and FLED2 flash mode is controlled by LED_EN DEFAULT VALUE 00 000 000 ______________________________________________________________________________________ 31 MAX8834Y/MAX8834Z Table 8. LED_CNTL MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 9. TMR_DUR This register contains watchdog timer and flash safety time-control values. REGISTER NAME Address 0x0A Reset Value 0x00 Type Read/write Special Features — BIT NAME B7 (MSB) WDT_EN B6 B5 B4 WDT_DUR[1:0] TMR_MODE B3 B2 TMR_DUR [3:0] B1 B0 (LSB) 32 TMR_DUR DESCRIPTION Enable/Disable Of Watchdog Timer Function 0 = WDT is disabled 1 = WDT is enabled Watchdog Timer Duration 00 = 4s 01 = 8s 10 = 12s 11 = 16s Safety Timer Control 0 = One-shot mode—generates a flash with a duration of TMR_DUR regardless of LED:EN and I2C setting; pulling VDD low in this condition terminates flash operating and puts the IC into power-down mode 1 = Maximum timer mode—ensures that flash duration does not exceed the timer defined in 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 0 00 0 0000 Adaptive Step-Up Converters with 1.5A Flash Driver This register contains NTC function control values. REGISTER NAME Address 0x0B Reset Value 0x00 Type Read/write Special Features BIT B7 (MSB) B6 NTC_CNTL — NAME DESCRIPTION Flash Safety Timer Reset Control 0 = Enable FLASH reset timer, only valid when FLASH mode is enabled using the LED_EN; LED_EN needs to be pulled low for FLASH_TMR_CNTL minimum 30ms (typ) to reset the flash safety 1 = Disable FLASH reset timer; flash safety timer is reset as soon as LED_EN is pulled low — Reserved for future use DEFAULT VALUE 0 0 B5 — Reserved for future use 0 B4 — 0 B3 NTC_EN Reserved for future use Finger-Burn Feature Enable 0 = Disable NTC function 1 = Enable NTC function B2 B1 B0 (LSB) NTC[2:0] Finger-Burn Threshold Control 000 = 200mV 001 = 250mV 010 = 300mV 011 = 350mV 100 = 400mV 101 = 450mV 110 = 500mV 111 = 550mV 0 000 ______________________________________________________________________________________ 33 MAX8834Y/MAX8834Z Table 10. NTC_CNTL MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 11. GSMB_CUR This register contains FLED1 and FLED2 current control values for the GSMB function. REGISTER NAME GSMB_CUR Address 0x0C Reset Value 0xC0 Type Read/write Special Features — BIT NAME B7 (MSB) GSMB_EN GSM Blank Enable 0 = GSMB input is disabled 1 = GSMB input is enabled 1 B6 GSMB_POL GSM Blank Polarity Control 0 = GSMB is active-low 1 = GSMB is active-high 1 B5 B4 ILIM[3:0] B3 B2 B1 HC_TMR[1:0] B0 (LSB) 34 DESCRIPTION DEFAULT VALUE 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 00 = 10μs 01 = 20μs 10 = 40μs 11 = 80μs ______________________________________________________________________________________ 0000 00 Adaptive Step-Up Converters with 1.5A Flash Driver This register contains MAXFLASH control function. REGISTER NAME Address 0x0D Reset Value 0x00 Type Read/write Special Features BIT B7 (MSB) — NAME LB_EN LB_TH[4:0] LB_HYS[1:0] Low-Battery Detection Hysteresis 00 = 100mV 01 = 200mV 10 = Reserved for future use 11 = Hysteresis is disabled—flash current is only reduced B5 B3 B2 B1 B0 (LSB) DESCRIPTION MAXFLASH Function Enable 0 = Disabled 1 = Low-battery function is enabled Low-Battery Detection Threshold 00000 = 2.400V [Do not use] 00001 = 2.433V [Do not use] 00010 = 2.466V [Do not 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 B6 B4 MAXFLASH1 DEFAULT VALUE 0 00000 00 ______________________________________________________________________________________ 35 MAX8834Y/MAX8834Z Table 12. MAXFLASH1 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 13. MAXFLASH2 This register contains MAXFLASH control function. REGISTER NAME MAXFLASH2 Address 0x0E Reset Value 0x00 Type Read/write Special Features — BIT NAME B7 (MSB) — Reserved for future use DESCRIPTION 0 B6 — Reserved for future use 0 B4 — Reserved for future use 0 B3 — Reserved for future use 0 B3 — Reserved for future use 0 B2 — Reserved for future use 0 Low-Battery Reset Timer 00 = 0.250ms 01 = 0.500ms 10 = Reserved for future use 11 = Reserved for future use 00 B1 LB_TMR[1:0] B0 (LSB) DEFAULT VALUE Table 14. WDT_RST This register contains watchdog reset function. REGISTER NAME WDT_RST Address 0x16 Reset Value 0x00 Type Read/write Special Features BIT NAME DESCRIPTION DEFAULT VALUE B7 (MSB) — Reserved for future use 0 B6 — Reserved for future use 0 B4 — Reserved for future use 0 B3 — Reserved for future use 0 B3 — Reserved for future use 0 B2 — Reserved for future use 0 B1 — Reserved for future use 0 — Watchdog Reset 0 = Default 1 = Writing a 1 resets the watchdog timer; after writing a 1, this bit is cleared upon watchdog timer reset — B0 (LSB) 36 — ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver This register contains status information. REGISTER NAME Address STATUS1 0x17 Reset Value N/A Type Read Special Features — BIT NAME DESCRIPTION DEFAULT VALUE B7 (MSB) NTC_FLT NTC Status Readback 0 = NTC status OK 1 = Fault (short) occurred on NTC 0 B6 GSMB GSMB Status Readback 0 = No GSMB event has occurred 1 = GSMB event has occurred 0 B5 POK_FLT POK Window Cooperator Status Readback 0 = Output voltage is within POK window 1 = POK fault has occurred 0 B4 OVER_TEMP Die Temperature Overload Condition Status Readback 0 = Die temp is within spec 1 = Die overtemp event has occurred 0 B3 NTC_OVT NTC Status Readback 0 = NTC temperature is within spec 1 = NTC temperature threshold has tripped 0 B2 INDLED_FLT INDLED Status Readback 0 = INDLED status is OK 1 = Fault (open/short) has occurred on INDLED 0 B1 FLED2_FLT FLED2 Status Readback 0 = FLED2 status is OK 1 = Fault (open/short) has occurred on FLED2 0 B0 (LSB) FLED1_FLT FLED1 Status Readback 0 = FLED1 status is OK 1 = Fault (open/short) has occurred on FLED1 0 Note: All faults are latched. Bit(s) are cleared after reading register contents. If the fault is still present, the bit is set again. ______________________________________________________________________________________ 37 MAX8834Y/MAX8834Z Table 15. STATUS1 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 16. STATUS2 This register contains status information. REGISTER NAME STATUS2 Address 0x18 Reset Value N/A Type Read Special Features BIT — NAME DESCRIPTION DEFAULT VALUE B7 (MSB) MAXFLASH_STAT B6 GSMB_ILIM B5 — Indication of if MAXFLASH Function Has Been Triggered Since Last Read Operation of This Register 0 = MAXFLASH event has not occurred 1 = MAXFLASH event has occurred Indication of if Input Current Limit Has Been Reached During GSMB Since Last Read Operation of This Register 0 = Input current limit not reached 1 = Input current limit reached Reserved for future use B4 — Reserved for future use 0 B3 — Reserved for future use 0 B2 — Reserved for future use 0 B1 — Reserved for future use 0 B0 (LSB) — Reserved for future use 0 0 0 0 Table 17. CHIP_ID1 This register contains the MAX8834Y/MAX8834Z die type number. REGISTER NAME CHIP_ID1 Address 0x1A Reset Value N/A Type Read Special Features BIT — NAME DESCRIPTION DEFAULT VALUE B7 (MSB) B6 B5 DIE_TYPE[7:4] BCD Character 1 [0001] DIE_TYPE[3:0] BCD Character 1 [0001] B4 B3 B2 B1 B0 (LSB) Note: This register value is fixed in metal. 38 ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver This register contains the die type dash number (0 = plain) and mask revision level. REGISTER NAME CHIP_ID2 Address 0x1B Reset Value N/A Type Read Special Features BIT — NAME DESCRIPTION DEFAULT VALUE B7 (MSB) B6 DASH B5 BCD Character representing dash number — BCD Character representing die revision — B4 B3 B2 MASK_REV B1 B0 (LSB) Applications Information Inductor Selection See Table 19 for a list of recommended inductors. To prevent core saturation, ensure that the inductor saturation current rating exceeds the peak inductor current for the application. Calculate the worst-case peak inductor current as follows: IPEAK = VOUT × IOUT(MAX) 0.9 × VIN(MIN) + VIN(MIN) 2 × fSW × L where fSW is the switching frequency. Capacitor Selection Bypass IN to AGND and PGND with a ceramic capacitor. Ceramic capacitors with X5R and X7R dielectrics are recommended for their low ESR and tighter tolerances over wide temperature ranges. Place the capacitor as close as possible to the IC. The recommended minimum value for the input capacitor is 10µF; however, larger value capacitors can be used to reduce input ripple at the expense of size and higher cost. The output capacitance required depends on the output current. A 10µF ceramic capacitor works well in most situations, but a 4.7µF ceramic capacitor is acceptable for lower load currents. Compensation Network Selection The step-up converter is compensated for stability through an external compensation network from COMP to AGND. See Table 20 for recommended compensation networks. PCB Layout Due to fast-switching waveforms and high-current paths, careful PCB layout is required. Connect AGND, FGND, and PGND directly to the ground plane. The IN bypass capacitor should be placed as close as possible to the IC. RCOMP and CCOMP should be connected between COMP and AGND as close as possible to the IC. Minimize trace lengths between the IC and the inductor, the input capacitor, and the output capacitor; keep these traces short, direct, and wide. The ground connections of C IN and C OUT should be as close together as possible and connected to PGND. The traces from the input to the inductor and from the output capacitor to the LEDs may be longer. Figure 21 illustrates an example PCB layout and routing scheme. Refer to the MAX8834Y/MAX8834Z Evaluation Kit for a PCB layout example. ______________________________________________________________________________________ 39 MAX8834Y/MAX8834Z Table 18. CHIP_ID2 MAX8834Y/MAX8834Z Adaptive Step-Up Converters with 1.5A Flash Driver Table 19. Suggested Inductors MANUFACTURER Coilcraft Taiyo Yuden TOKO PART/SERIES INDUCTANCE (μH) DCR (m) ISAT (A) DIMENSIONS (lTYP x W TYP x HMAX) (mm) LPS4012-222ML 2.2 100 2.3 4 x 4 x 1.1 LPS4018-222ML 2.2 70 2.7 4 x 4 x 1.7 LPS5030-220ML 2.2 57 3.1 5 x 5 x 2.9 LPS6225-222ML 2.2 45 3.9 6.2 x 6.2 x 2.5 LPO3310-102ML 1 76 1.6 3x3x1 LPS3015-102ML 1 75 1.6 3x3x1 LPO3010-102NLC 1 140 1.7 3x3x1 DO3314-102ML 1 110 2.1 3 x 3 x 1.4 LPS3314-102ML 1 45 2.3 3 x 3 x 1.4 DP1605T-102ML 1 40 2.5 4 x 4 x 1.8 LPS4012-102ML 1 60 2.8 4 x 4 x 1.1 LPS4018-102ML 1 40 2.8 4 x 4 x 1.7 LPS5015-102ML 1 50 3.8 5 x 5 x 1.5 NR4018T2R2M 2.2 72 2.7 4 x 4 x 1.8 NR3012T1R0N 1 60 1.5 3 x 3 x 1.2 NR4010T1R0N 1 120 1.8 4x4x1 NR3015T1R0N 1 36 2.1 3 x 3 x 1.5 NR4012T1R0N 1 72 2.5 4 x 4 x 1.2 4 x 4 x 1.8 NP03SB1R0M 1 27 2.6 NP04SZB1R0N 1 30 4 5x5x2 NR4018T1R0N 1 36 4 4 x 4 x 1.8 1117AS-1R2N 1.2 65 1.2 3x3x1 1098AS-1R2N 1.2 56 1.8 3 x 3 x 1.2 A997AS-1R0N 1 40 1.8 4 x 4 x 1.8 1072AS-1R0N 1 30 1.95 3 x 3 x 1.8 1071AS-1R0N 1 40 2.1 3 x 3 x 1.5 Table 20. Suggested Compensation Networks INDUCTANCE RCOMP (k) CCOMP (pF) 1.0μH Inductor (dynamic loads) 5.5 2200 2.2μH Inductor (dynamic loads) 4.3 2200 4.7μH Inductor (dynamic loads) 3 4700 10μH Inductor (dynamic loads) 3 6800 Other (non-LED) Loads (1μH to 10μH) 0 (short) 22000 40 ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z L 6.0mm COUT CIN OUT LX PGND IN VDD A1 A2 A3 A4 A5 OUT LX PGND SCL AGND B1 B2 B3 B4 B5 COMP FGND LED_EN GSMB SDA C1 C2 C3 C4 C5 FLED2 FGND FLED1 INDLED NTC D1 D2 D3 D4 D5 CVDD CCOMP FLASH2 LED CATHODE FLASH1 LED CATHODE INDICATOR LED CATHODE 3.8mm Figure 21. Recommended PCB Layout ______________________________________________________________________________________ 41 Adaptive Step-Up Converters with 1.5A Flash Driver MAX8834Y/MAX8834Z Block Diagram and Typical Application Circuit 1μH LX OUT IN VIN 2.5V TO 5.5V CIN 10μF AGND UVLO AND POWER INPUT CURRENT LIMIT COMP CCOMP COUT 10μF PWM STEP-UP CONVERTER ADAPTIVE/ FIXED OUTPUT SELECT PGND PROGRAMMABLE OUTPUT 3.7V TO 5.2V VREF VREG 2MHz OR 4MHz SELECT MIN RCOMP FLASH TIMER VPOK 750mA WATCHDOG TIMER NTC RNTC 100kΩ GSMB REGISTERS AND CONTROL LOGIC PA_EN 1MHz VLOGIC 1.62V TO 3.6V 750mA 16mA SAMPLING LOGIC FGND VDD CVDD 0.1μF 42 FLED2 INDLED FLASH/MOVIE LED_EN STROBE I2C INTERFACE FLED1 SDA SCL I2 C INTERFACE MAX8834Y MAX8834Z ______________________________________________________________________________________ Adaptive Step-Up Converters with 1.5A Flash Driver Chip Information PROCESS: BiCMOS TOP VIEW (BUMPS ON BOTTOM) 1 2 3 4 5 MAX8834Y/MAX8834Z A B C D Package Information For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. A1 A2 A3 A4 A5 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. OUT LX PGND IN VDD 20 WLP W202A2+2 21-0059 B1 B2 B3 B4 B5 OUT LX PGND SCL AGND C1 C2 C3 C4 C5 COMP FGND LED_EN GSMB SDA D1 D2 D3 D4 D5 FLED2 FGND FLED1 INDLED NTC WLP (2.5mm × 2.0mm) Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 43 © 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX8834Y/MAX8834Z Pin Configuration