A Compact Switched-Capacitor Regulated Charge Pump Power Supply

A CMOS switched-capacitor reference is combined with a switched-capacitor voltage doubling charge pump to produce a compact regulated 3.2-V power supply from an input that ranges from 1.8 to 3.5 V. It can supply up to 6 mA at minimum input. The switched-capacitor topology uses a single PN junction and could allow for inputs and outputs less than 1 V. The concept of constant frequency charge pump regulation is discussed, as is the theory behind stability, load regulation, and efficiency. Measured results from a 0.5-mum CMOS process are given