The TPS6012x step-up, regulated charge pumps generate a 3.3-V or 3-V 4% output voltage from a 1.8-V to 3.6-V input voltage (two alkaline, NiCd, or NiMH batteries). They can deliver an output current of at least 200 mA (100 mA for the TPS60122 and 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.