A fast transient response on-chip low-dropout regulator

Abstract

Abstract： Based on dual active feedback with miller capacitor compensation (DAFMCC), a novel single pole system of capacitor-less on-chip low-dropout (LDO) voltage regulator circuit is presented. The LDO adopts a fully differential amplifier as the first gain stage, two parallel feedforward pathways can improve the transient response performance of the circuit meanwhile insert a push-pull stage at the gate of the power MOSFET which results in a symmetrical slewing behavior. The proposed LDO regulator is verified by TSMC 0.18 µm BCD process. The simulation results show that when supply voltage changes from 2 V to 4 V, the minimum dropout voltage is 200 mV, the maximum load current is 120 mA. The transient response recovery time is smaller than 0.7 µs, the phase margin is larger than 60°.

Keywords

• ldo
• capacitor-less
• fast transient response
• frequency compensation