The LTC3202 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 125mA from a 2.7V to 4.5V input. Low external parts count (two flying capacitors and two small bypass capacitors at VINand 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 short-circuit from VOUTto 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 VINand reduces quiescent current to less than 1µA.The LTC3202 is available in the 10-pin MSOP and 3mm x 3mm DFN packages.ApplicationsWhite LED BacklightingProgrammable Boost Current Source