The TPS60251 is a high efficiency, constant frequency charge pump DC/DC converter that uses a dual mode 1× and 1.5× conversion to maximize efficiency over the input voltage range. It drives up to five white LEDs for a main display and up to two white LEDs for a sub display with regulated constant current for uniform intensity. By utilizing adaptive 1×/1.5× charge pump modes and very low-dropout current regulators, the TPS60251 achieves high efficiency over the full 1-cell lithium-battery input voltage range.

Four enable inputs, ENmain, ENsub1, ENsub2, and ENaux, available through I²C, are used for simple on/off controls for the main, sub1, sub2, and DM5 displays, respectively. To lower operating current when using one sub display LED, the device provides independent operation in sub display LEDs.