A 28-NM CMOS High PSRR and Stability Low Dropout Regulator Using Feed-Forward with Current Sensing

This paper presents an innovative approach for achieving high power supply rejection ratio (PSRR) and stability in low drop-out (LDO) regulators, which are critical components in system-on-chip (SoC) chips. The feedforward method improves PSRR levels in LDO regulators by adding a compensating signal proportional to power supply noise to the output voltage, thus reducing the impact of the noise on the output voltage. To ensure stability, the LDO regulator is designed with current sensing. The proposed LDO has been fabricated based on 28nm CMOS process and regulates the output at 1V from a 1.2V supply. The measured PSRR has an enhancement of -39dB at 10kHz when compared of an LDO with no enhancement and has low overshoot and undershoot.