A dual-phase charge pump circuit with compact size

Abstract

In this paper, a regulated dual-phase charge pump with compact size is presented. By means of a nano-ampere switched-capacitor voltage reference (SCVR) circuit, the dual-phase charge pump regulator can reduce the quiescent current and the output ripple. Besides, a new power stage is proposed to define the stability of the overall system. Owing to the design of buffer stage, the charge pump regulator can extend bandwidth and increase phase margin. Thus, the transient response and driving capability can be improved. Beside, the proposed automatic body switching circuit can efficiently drive the bulk of the power p-type MOSFETs to avoid leakage and potential latch-up. This chip was fabricated by TSMC 0.35 mu m, 3.3 V/5 V 2P4 M CMOS technology. The input voltage range varies from 2.9 to 4.9 V for the lithium battery and the output voltage is regulated at 5 V. Experimental results demonstrate the charge pump can provide 50 mA maximum load current without any oscillation problems.