The TPS6012x step-up, regulated charge pumps generate a 3.3-V 4% output voltage from a 1.8-V to 3.6-V input voltage (two alkaline, NiCd, or NiMH batteries). The output current is 200 mA for the TPS60120/TPS60121 and 100 mA for the TPS60122/TPS60123, all from a 2-V input. Four external capacitors are needed to build a complete high efficiency dc/dc charge pump converter. To achieve the high efficiency over a wide input voltage range, the charge pump automatically selects between a 1.5x or doubler conversion mode. From a 2-V input, all ICs can start with full load current.