A low power LDO with high PSR over a wide frequency range based on an impedance attenuation buffer

Abstract

A low-dropout voltage linear regulator with low quiescent current and high PSR over a wide frequency range is designed to meet the application requirements of high-performance CMOS image sensor. An embedded impedance attenuation buffer is proposed to embed the feedforward path into the buffer, reduce the quiescent current and improve PSR in a wide frequency range. The simulation result shows that LDO achieves a PSR better than 60dB up to 10MHz for load current up to 100mA. The LDO achieves 65dB PSR at 1MHz and 90dB PSR at 1KHz. LDO consumes a quiescent current of 36uA with a bandgap reference circuit included.