A Wide Input Voltage Range LDO with Fast Transient Response

A flipped voltage follower (FVF) based low-dropout (LDO) regulator with a wide input voltage range, which could be used in power-driving chips, is proposed and simulated in a standard 0.18µm BCD process in this paper. The proposed LDO could achieve a fast transient response and have a wide input voltage range using the dual loop structure. The simulation results show that the proposed linear regulator could be regulated to 5.0V in a wide input range of 8-45V, and PSRR is −88.74dB when working at low-frequency. Moreover, PSRR at 1MHz is still −70.24dB. The output changes by 1.47mV when input voltage changes from 8V to 45V. When input voltage is 24V and load current varies from 1µA to 50mA, the output changes by 9.06µV at TT corner. For large load transient of 1µA to 50mA and back to 1µA, the simulated overshoot and undershoot is 68.43mV and 75.7mV, with recovery time being 26ns and 102ns at TT process corner.