A Voltage Error Quantizer For Digital Low Dropout Regulators With Fast Transient Response and Low Steady-State Error

This paper proposes a voltage error quantizer for digital low dropout regulators (DLDOs) with fast transient response and low steady-state error. Compared with traditional DLDOs quantizing the reference voltage and output voltage separately, the proposed voltage error quantizer quantifies the voltage difference directly with high quantization speed and accuracy. Implemented in 28nm CMOS process, the proposed quantizer with on-chip self-calibration identifies the voltage difference as small as 4mV and has stable output codes at sampling frequencies up to 500MHz, which satisfies the fast transient response and low steady-state error demands of DLDOs.