A High PSR and Fast Transient Response Output-Capacitorless LDO using Gm-Boosting and Capacitive Bulk-Driven Feed-Forward Technique in 22nm CMOS

Abstract

This paper presents an output-capacitorless low-dropout regulator (OCL-LDO) using capacitive bulk-driven feed-forward (CBDFF) technique and an adaptive-biasing error amplifier with gm-boosting to enhance the power supply rejection (PSR) and the transient response. The proposed OCL-LDO has been implemented in a 22nm CMOS technology. It consumes a quiescent current of 49 µA from a power supply of 1.05-1.25 V and has a dropout voltage of 200 mV. The OCL-LDO achieves -84 dB PSR at low frequency and -69 dB PSR at 1 MHz for the load current of 20 mA. It achieves a line regulation of 0.18 mV/V, a load regulation of 0.77 µV/mA, and a settling time of 135 ns.