Regulated Switched-Capacitor Doubler With Interleaving Control for Continuous Output Regulation Feng Su, Student Member , IEEE

Abstract

A dual-branch 1.8 V to 3.3 V regulated switched-ca- pacitor voltage doubler with an embedded low dropout regulator is presented. For the power stage, the power switches are individually controlled by their phase signals using a phase-delayed gate drive scheme, and are turned on and off in proper sequence to elimi- nate both short-circuit and reversion currents during phase transi- tions. For the regulator , the two branches operate in an interleaving fashion to achieve continuous output regulation with small output ripple voltage. Dual-loop feedback capacitor multiplier is adopted for loop compensation and a P-switch super source follower with high current sinking capability is inserted to drive switching capac- itive load, and push the pole at the gate of the output power tran- sistor to high frequency for better stability. The regulated doubler has been fabricated in a 0.35 m CMOS process. It operates at a switching frequency of 500 kHz with an output capacitor of 2 F, and the maximum output voltage ripple is only 10 mV for a load current that ranges from 10 mA to 180 mA. The load regulation is 0.0043%/mA, and the load transient is 7.5 s for a load change of 160 mA to 10 mA, and 25 s for a load change of 10 mA to 160 mA.