Novel CMOS Bulk-driven Charge Pump for Ultra Low Input Voltage

Abstract

In this paper, a novel bulk-driven cross-coupled charge pump designed in standard 90 nm CMOS technology is presented. The proposed charge pump is based on a dynamic threshold voltage inverter and is suitable for integrated ultra-low voltage converters. Due to a latchup risk, bulk-driven charge pumps can safely be used only in low-voltage applications. For the input voltage below 200 mV and output current of 1 uA, the proposed bulk-driven topology can achieve about 10 % higher efficiency than the conventional gate-driven cross-coupled charge pump. Therefore, it can be effectively used in DC-DC converters, which are the basic building blocks of on-chip energy harvesting systems with ultra-low supply voltage.