High PSRR Low Drop-Out Voltage Regulator with Low Recovery Time, Low Line Regulation and -75 dB PSRR

A low drop-out voltage (LDO) regulator and a bandgap voltage reference circuits are proposed in this paper. Its regulated output voltage is 1.2 V to provide 0-100 mA of current with a power supply of 1.4-2 V. The regulator consisted of a feedback loop included an operational amplifier, pass element, and voltage reference. The voltage reference is 0.9 volt, and the heat coefficient is lower than 100 ppm/ºC in a thermal range of 0-90 ºC. The important point in LDO is the stability of the loop. In order to stabilize the loop, a large capacitor is used. Quiescent current is less than 110μA. Simulation results show improvement in transient response and PSRR. The proposed technique has the advantages of simulated PSRR of -75dB at less than 8KHz frequency. Simulations results show that the achieved line regulation is 1m V/V and the load regulation is 55 μV/mA. Besides, improved recovery time is 2.42 μs.

Keywords:

Voltage drop , Bandgap reference , LDO regulator