TPS60111

The TPS60111 step-up, regulated charge pump generates a 5-V ±4% output voltage from a 2.7-V to 5.4-V input voltage (three alkaline, NiCd, or NiMH batteries; or, one lithium or lithium ion battery). Output current is 150 mA from a 3-V input. Only four external capacitors are needed to build a complete low-noise dc/dc converter. The push-pull operating mode of two single-ended charge pumps assures the low output voltage ripple as current is continuously transferred to the output. From a 3-V input, the TPS60111 can start into full load with loads as low as 33 Ω.

The TPS60111 features either constant frequency mode to minimize noise and output voltage ripple or the power-saving pulse-skip mode to extend battery life at light loads. The TPS60111 switching frequency is 300 kHz. The logic shutdown function reduces the supply current to 1-µA (max) and disconnects the load from the input. Special current-control circuitry prevents excessive current from being drawn from the battery during start-up. This dc/dc converter requires no inductors and has low EMI. It is available in the small 20-pin TSSOP PowerPAD^TM package (PWP).