LTC3202 Datasheet | Linear Technology

LTC3202 Low Noise, High Efficiency Charge Pump for White LEDs Features s s s s s s s s s s s DESCRIPTIO U APPLICATIO S s s Low Noise Constant Frequency Operation 25% Less Input Current Than Doubler Charge Pump High Output Current: Up To 125m A Small Application Circuit Regulated Output Voltage or Current Automatic Soft-Start VIN Range: 2.7V to 4.5V No Inductors 1.5MHz Switching Frequency ICC < 1µA in Shutdown Available in 10-Pin MSOP and 3mm × 3mm DFN Packages The LTC®3202 is a low noise, constant frequency charge pump DC/DC converter that uses fractional conversion to increase efficiency in white LED applications. The part can be used to produce a regulated voltage or current of up to 125m A from a 2.7V to 4.5V input. Low external parts count (two flying capacitors and two small bypass capacitors at VIN and VOUT) make the LTC3202 ideally suited for small, battery-powered applications. An internal 2-bit DAC allows LED current to be adjusted for LED brightness control. The LTC3202 also has thermal shutdown protection and can survive a continuous shortcircuit from VOUT to GND. Built-in soft-start circuitry prevents excessive inrush current during start-up. High switching frequency enables the use of small external capacitors. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to less than1µA. The LTC3202 is available in the 10-pin MSOP and 3mm × 3mm DFN packages. , LTC and LT are registered trademarks of Linear Technology Corporation. White LED Backlighting Programmable Boost Current Source TYPICAL APPLICATIO C2 1µF C3 1µF Programmable White LED Power Supply Input and Output Ripple VIN (AC COUPLED) 20m V/DIV 8 C1+ 10 CURRENT PROGRAMMING VIN 3V TO 4.5V C1 1µF 1 4 D0 D1 VIN 7 C1- 0m A TO 125m A C2+ C2- 3 TOTAL CURRENT VOUT LTC3202 FB GND 5, 11 2 C4 1µF 36Ω 36Ω 36Ω 36Ω 36Ω 36Ω VOUT (AC COUPLED) 20m V/DIV 500ns/DIV VIN = 3.6V CIN = COUT = 1µF IOUT = 60m A 3202 G09 C1, C2, C3, C4 = MURATA GRM 39X5R105K6.3 OR TAIYO...