A 1.2 V 250 mA Low-Dropout Voltage Regulator in 180nm Bulk CMOS Process

A 1.2 V 250 mA CMOS low-dropout voltage regulator (LDOVR) targeting radio frequency (RF) system-onchip (SoC) applications is proposed in this paper. The LDOVR comprises a bandgap reference source, an error amplifier, a pushpull amplifier (PPA), a power output stage, and a startup circuit. By employing a topology that combines folded cascode and singlestage common-source configurations, along with nested Miller compensation techniques, the error amplifier achieves high gain and stability. The meticulously designed push-pull amplifier boosts the switching speed of the power transistor gate voltage, thereby enhancing the transient response. The proposed LDOVR is designed and implemented using a 180 nm bulk CMOS process. Simulation results demonstrate that the LDOVR can handle a wide range of input voltage variations, maintaining a stable output of 1.2 V with a deviation of less than $1 \%$ for input voltages ranging from 2.8 V to 5 V. Across a wide temperature range of -40 to $150^{\circ} \mathrm{C}$, the LDOVR exhibits a temperature coefficient better than $7.19 \mathrm{ppm} /{ }^{\circ} \mathrm{C}$. With a load current of up to 250 mA, the LDOVR maintains a phase margin close to 60° and a power supply rejection ratio (PSRR) greater than 50 dB at 100 kHz.