Low-Dropout Regulator design with a simple structure for good high frequency PSRR performance based on Bandgap Circuit

Abstract

This paper describes an op-amp free low-dropout regulator with a high PSRR over a broad frequency range. The design merges the high PSRR bandgap and LDO without op-amp involved and thus greatly reduces the silicon area. As no high impedence node engaged in the circuit, it is easy to achieve a good high frequency PSRR performance by using a locally regulated supply voltage. The op-amp free LDO is then developed by embedding replica technique in the bandgap. The circuit is evaluated with HHGrace 0.35µm CMOS technology. It generates a reference voltage of 1.152V and has a temperature coefficient of 0.01mV/K at 27C. LDO has a PSRR of −96dB at DC and still −48.5dB at 1MHz.