Design of low-power, fast-transient-response, capacitor-less low-dropout regulator for mobile applications

Abstract

This paper presents a capacitor-less low-dropout (LDO) regulator for on-chip mobile applications. An additional push-pull current with a capacitive coupling circuit is proposed to significantly enhance the transient response of the LDO regulator. The proposed LDO regulator can deliver an output current of 100 mA with a minimum dropout voltage of 0.4 V. The circuit was modeled and implemented in a 0.35-µm CMOS process with a die area of 0.22 mm². The experimental results show that the LDO regulator can be recovered within 0.5 µs at a voltage spike less than 90 mV.