LTC3218 400mA Single Wire Camera LED Charge Pump FEATURES DESCRIPTION Low Noise Constant-Frequency Operation The LTC 3218 is a low-noise, high-current charge pump Multi-Mode Operation: 1x or 2x Boost Mode DC/DC converter capable of driving high current LEDs at up Automatic Mode Switching to 400mA from a 2.9V to 4.5V input. A low external parts High Output Current: 150mA (Continuous), 400mA count (one ying capacitor, two programming resistors and (Pulsed) From Li-Ion/Polymer Input two bypass capacitors at V and CPO) make the LTC3218 IN 2-Second Flash Current Timeout for LED Protection ideally suited for small, battery-powered applications. Automatic Soft-Start Built-in soft-start circuitry prevents excessive inrush cur- Output Disconnect rent during start-up. High switching frequency enables the No Inductors use of small external capacitors. A built-in 2-second timer 220m Internal High Side Current Sense Resistor protects the LED during ash mode. Single Resistor Programming Capability Output current level is programmed by an external re- Tiny Application Circuit (3mm 2mm DFN Package, sistor. LED current is regulated using an internal high All Components < 1mm High) side 220m sense resistor. Automatic mode switching optimizes ef ciency by monitoring the voltage across the APPLICATIONS charge pump and switching modes only when dropout LED Torch/Flash Supply for DSCs/Cellphones is detected. The part is available in a low pro le 3mm 2mm 10-lead DFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6411531. TYPICAL APPLICATION Ef ciency vs V IN 100 2.2F 90 CP CM 80 2.9V TO 4.5V V CPO IN 4.7F 2.2F LTC3218 70 I DISABLED LED 60 ENF ENABLED LED DISABLED ENT GND ENABLED AOT2015 50mA 50 150mA I I SETF SETT 300mA ENF ENT I LED 40 3.7 3.9 2.9 3.1 3.3 3.5 4.1 4.3 4.5 0 0 0 (SHUTDOWN) 10.2k V (V) IN 0 1 100mA (TORCH) 1% 3218 TA01b 1 0 290mA 1 1 390mA (FLASH) 3218 TA01 3218fb 1 EFFICIENCY (%)LTC3218 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW V to GND ................................................... 0.3V to 6V IN 1 10 CP V IN CPO to GND ................................................ 0.3V to 6V 2 9 CPO CM ENF, ENT ........................................... 0.3V to V + 0.3V IN 3 11 8 I GND LED I , I (Note 2) ...............................................500mA CPO ILED 4 7 ENT ENF CPO Short-Circuit Duration .............................. Inde nite 5 6 I I SETT SETF Storage Temperature Range ................... 65C to 125C DDB PACKAGE Operating Temperature Range (Note 3).... 40C to 85C 10-LEAD (3mm 2mm) PLASTIC DFN T = 125C, = 76C/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 LTC3218EDDB PBF LTC3218EDDB TRPBF LCHS 10-Lead (3mm 2mm) 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: