TPS60231

· White LED Backlight for Color Displays in Cellular Phones, Smart Phones, PDAs, Handheld PCs, Digital Cameras, and Camcorders
· Keypad Backlight

The TPS60231 charge pump is optimized for white LED supplies in color display backlight applications. The device provides a constant current for each LED,which the initial value can be set by an external resistor. The supply voltage ranges from 2.7 V to 6.5 V and is ideally suited for all applications powered by a single LI-Ion battery cell or three to four NiCd, NiMH, or alkaline battery cells. Over an input voltage range from 3.1 V to 6.5 V, the TPS60231 provides a high output current of up to 25 mA per LED with a total of75 mA. High efficiency is achieved by utilizing a 1x/1.5x fractional conversion technique in combination with very low dropout current sources. In addition, the current controlled charge pump ensures low input current ripple and EMI. Only two external1 µF and two 0.47 µF capacitors are required to build a complete small and low cost power supply solution. To reduce board space to a minimum, the TPS60231 switches at 1 MHz operating frequency and is available in a small 16-pin QFN (RGT) package.