5-channel, current-regulated 125-mA charge pump for white LED backlight in 3x3 QFN

The TPS60230 charge pump is optimized for white LED supplies in backlit color display applications. The device provides a constant current, set by an external resistor, for each LED. 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. The TPS60230 provides up to 25 mA per LED, for a total of 125 mA, for input voltages ranging from 3.1 V to 6.5 V. High efficiency is achieved by utilizing a 1x/1.5x fractional conversion technique in combi- nation with very low dropout current sources. Additionally, the current controlled charge pump ensures low input current ripple and EMI. Only two external 1 µF and two 0.47 µF capacitors are required to build a complete small and low cost power supply solution. The TP60230 switches at 1 MHz operating frequency and is available in a small 16-pin QFN (RGT) package to keep board space to a minimum.