The LM2751 is a constant frequency switched capacitor charge pump with regulated output voltage options of 4.5V, and 5.0V. Over the input voltage range of 2.8V to 5.5V the LM2751 provides up to 150mA of output current and requires only four low-cost ceramic capacitors. The LM2751 provides excellent efficiency without the use of an inductor by operating the charge pump in a gain of 3/2 or 2. The proper gain for maintaining regulation is chosen so that efficiency is maximized over the input voltage range.