Design of high PSRR linear regulator based on pre regulated Technology

A high PSRR (power supply rejection ratio) linear regulator is designed to meet the requirements of high PSRR and simple structure. The circuit is based on the pre voltage regulation technology, using the stability characteristics of Zener diode to increase the input range of power supply voltage. The pre voltage regulation circuit can better reduce the interference of power supply voltage, improve the power suppression ratio of the circuit, and use Miller compensation to ensure the stability of the circuit. The whole circuit is simulated by Huahong NEC 0.35 μ m BCD process model. The simulation results show that the PSRR of the linear regulator can reach - 136dB at low frequency, the whole circuit can work normally at 6 ~ 30V supply voltage, the output voltage is 3.32v, the linear regulation rate is 0.018% / V, and the temperature coefficient is 7.8ppmz, which is suitable for electronic equipment using power management chip.