A low quiescent current high PSRR LDO circuit

Abstract

In order to meet the needs of Internet of Things devices and wearable electronic devices for lower standby power consumption and power supply noise, a Low Dropout Regulator (LDO) circuit with low quiescent current and high power supply rejection ratio is designed. The core circuit is bandgap and error amplifier. This design is based on the 0.18um BCD process. The Spectre simulation of Cadence has been used to test and simulate the circuit. The simulation result indicates that the bandgap voltage is 1.209V, the temperature coefficient is 19.76ppm/°C in the range of -25~125°C, and the power supply rejection ratio is 69dB at low frequency. The circuit can deliver a quiescent current of around 776nA and exhibits good temperature characteristics and low quiescent current.