LTC3214 500mA Camera LED Charge Pump FEATURES DESCRIPTION n Low Noise Constant Frequency Operation The LTC 3214 is a low noise, high current charge pump n High Ef ciency: Up to 94% DC/DC converter capable of driving high current LEDs at n Multi-Mode Operation: 1x, 1.5x or 2x Boost Modes up to 500mA from a 2.9V to 4.5V input. Low external parts n Automatic Mode Switching count (two ying capacitors, one programming resistor and n High Output Current: Up to 500mA two bypass capacitors at V and CPO) make the LTC3214 IN n Tiny Application Circuit (3mm 3mm DFN Package, ideally suited for small, battery-powered applications. All Components <1mm High) Built-in soft-start circuitry prevents excessive inrush cur- n Automatic Soft-Start rent during start-up. High switching frequency enables the n Output Disconnect use of small external capacitors. n Open, Shorted LED Protection n Output current level is programmed by an external resistor. No Inductors n LED current is regulated using an internal 110m sense Internal 110m LED Current Sense Resistor n resistor. Automatic mode switching optimizes ef ciency 3mm 3mm 10-Lead DFN Package by monitoring the voltage across the charge pump and switching modes only when dropout is detected. The APPLICATIONS part is available in a low pro le 3mm 3mm 10-lead DFN package. n LED Torch/Camera Light Supply for Cell Phones, L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. PDAs and Digital Cameras All other trademarks are the property of their respective owners. n General Lighting and/or Flash/Strobe Applications Protected by U.S. Patents including 6411531. TYPICAL APPLICATION Ef ciency vs V IN C1 C2 100 100mA 200mA 2.2F 2.2F 90 300mA 80 + + C1 C1 C2 C2 70 2.9V TO 4.5V V CPO 50mA IN 60 C LED C IN CPO 50 2.2F 4.7F LTC3214 40 I I LED LED UP TO 500mA 30 DISABLE ENABLE EN 0.11 20 I SET LED = AOT2015 10 V = 2.9V TYP AT 100mA F 0 R SET 2.9 3.7 4.1 4.3 3.1 3.3 3.5 3.9 4.5 V (V) IN 3214 TA01a 3214 TA01b LED: AOT2015 3214fb 1 EFFICIENCY (P /P ) (%) LED INLTC3214 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V to GND ............................................... 0.3V to 5.5V TOP VIEW IN CPO to GND ............................................. 0.3V to 5.5V + C2 1 10 C1 EN ................................................... 0.3V to V + 0.3V + IN C1 9 GND 2 I , I (Note 2) ...............................................600mA CPO 3 11 C2 8 CPO ILED 4 I 7 V CPO Short-Circuit Duration ............................. Inde nite LED IN I 5 6 EN SET Storage Temperature Range .................. 65C to 125C Operating Temperature Range (Note 3)... 40C to 85C DD PACKAGE 10-LEAD (3mm s 3mm) PLASTIC DFN T = 125C, = 43C/W JMAX JA EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC3214EDD PBF LTC3214EDD TRPBF LBVQ 10-Lead (3mm 3mm) Plastic DFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: