MAX8647/MAX8648 19-0790 Rev 1 9/07 Ultra-Efficient Charge Pumps for Six White/RGB LEDs in 3mm x 3mm Thin QFN General Description Features Six Adaptive Current Regulators The MAX8647/MAX8648 drive up to six white LEDs or two sets of RGB LEDs with regulated constant current Independent Voltage Supply for Each LED for display backlight and fun light applications. By utiliz- Individual LED Brightness Control (MAX8647) ing an inverting charge pump and extremely low- 24mA to 0.1mA Dimming Range dropout adaptive current regulators, these ICs achieve 2 I C Interface (MAX8647) very high efficiency over the full 1-cell Li+ battery volt- Serial-Pulse Dimming Logic (MAX8648) age range and even with large LED forward voltage mismatch. The 1MHz fixed-frequency switching allows 2% Accuracy, 0.4% Matching (typ) for tiny external components. The regulation scheme is Low 70A Quiescent Current optimized to ensure low EMI and low input ripple. The Low 1A Shutdown Current MAX8647/MAX8648 include thermal shutdown, open- Inrush Current Limit and short-circuit protection. T Derating Function Protects LEDs 2 A The MAX8647 features an I C serial port, while the MAX8648 features a three-wire serial-pulse logic inter- 16-Pin, 3mm x 3mm Thin QFN Package face. Both devices support independent on/off and dimming for main and subbacklights. The dimming Ordering Information ranges are pseudo-logarithmic from 24mA to 0.1mA and off in 32 steps. Both devices include a temperature PIN TOP PKG PART DIMMING derating function to safely allow bright 24mA full-scale PACKAGE MARK CODE output current setting while automatically reducing cur- 2 rent to protect LEDs at high ambient temperatures M A X86 4 7 E TE + I C interface 16 Thin Q FN-E P * AFD T1633-5 above +60C. S erial -p ul se The MAX8647/MAX8648 are available in a 16-pin, 3mm M A X86 4 8 E TE + 16 Thin Q FN-E P * AFE T1633-5 l ogic x 3mm thin QFN package (0.8mm max height). Note: All devices are specified over the -40C to +85C extended Applications temperature range. +Denotes a lead-free package. White LED Backlighting, Single or Dual Display *EP = Exposed paddle. Wide-Gamut RGB LED Display Backlighting Typical Operating Circuit Camera Flash or RGB Indicators Cellular Phones and Smartphones 1F 1F PDAs, Digital Cameras, and Camcorders Pin Configuration C1P C1N C2P C2N 1F INPUT NEG TOP VIEW 2.7V TO 5.5V IN EP 1F 12 11 10 9 GND WHITE 13 LED6 LED1 8 OR RGB LED MAX8648 D1 NEG SDA (ENC) 14 7 LED1 MAX8647ETE D2 SCL (ENB) 15 6 C1N LED2 MAX8648ETE D3 C2N ENA LED3 V (ENA) 16 5 DD + SERIAL- D4 132 4 PULSE ENB LED4 INTERFACE D5 ENC LED5 THIN QFN D6 LED6 ( ) DESIGNATE PINS ON THE MAX8648 Maxim Integrated Products 1 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. EVALUATION KIT AVAILABLE IN LED2 GND LED3 C1P LED4 C2P LED5Ultra-Efficient Charge Pumps for Six White/RGB LEDs in 3mm x 3mm Thin QFN ABSOLUTE MAXIMUM RATINGS V , IN, SCL, SDA, ENA, ENB, ENC to GND........-0.3V to +6.0V Continuous Power Dissipation (T = +70C) DD A V , IN, SCL, SDA, ENA, ENB, ENC to NEG........-0.3V to +6.0V 16-Pin Thin QFN 3mm x 3mm (derate 20.8mW/C DD NEG to GND.............................................................-6V to +0.3V above +70C).............................................................1667mW C2N to GND .............................................................-6V to +0.3V Junction Temperature......................................................+150C C1P, C2P to GND .......................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +150C IN C2P to C1N..................................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C IN LED , C1N, C2N to NEG .............................-0.3V to (V + 0.3V) IN 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 (V = V = 3.6V, V = 0V, T = -40C to +85C, unless otherwise noted. Typical values are at T = +25C.) (Note 1) VDD IN GND A A PARAMETER CONDITIONS MIN TYP MAX UNITS IN Operating Voltage 2.7 5.5 V V Operating Voltage 1.7 5.5 V DD Undervoltage-Lockout (UVLO) V rising 2.35 2.45 2.55 V IN Threshold Undervoltage-Lockout Hysteresis 100 mV T = +25C 0.4 2.5 IN Shutdown Supply Current V = V = V (MAX8647), A SCL SDA DD A (All Outputs Off) V = 0V (MAX8648) EN T = +85C 0.4 A T = +25C 0.1 1.0 A V Shutdown Supply Current A DD T = +85C 0.1 A Charge pump inactive, two LEDs enabled at 0.1mA 70 100 A setting IN Operating Supply Current Charge pump active, 1MHz switching, all LEDs 1.6 mA enabled at 0.1mA setting Charge pump inactive, two LEDs enabled at 0.1mA 0.1 1.0 setting, T = +25C A V Operating Supply Current A DD Charge pump active, 1MHz switching, all LEDs 0.1 enabled at 0.1mA setting, T = +85C A Thermal-Shutdown Threshold +160 C Thermal-Shutdown Hysteresis 20 C 2 I C INTERFACE (MAX8647) 0.7 x Logic-Input High Voltage (SDA, SCL) V = 1.7V to 5.5V, hysteresis = 0.2 x V (typ) V DD DD V DD 0.3 x Logic-Input Low Voltage (SDA, SCL) V = 1.7V to 5.5V, hysteresis = 0.2 x V (typ) V DD DD V DD Filtered Pulse Width (t)V = 2.7V to 5.5V, V = 1.7V to 5.5V (Note 2) 50 ns SP IN DD T = +25C -1 0.01 +1 A Logic-Input Current (SDA, SCL) V = 0V or V = 5.5V A IL IH T = +85C 0.1 A 2 MAX8647/MAX8648