LTC3202

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 125mA 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 125mA 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. ...