A fast transient response shunt low dropout regulator

In this paper, the proposed shunt regulator is presented. Compared with a series voltage regulator, the shunt voltage regulator gives wideband power supply rejection (PSR) and fast transient response at the expense of large quiescent current. In this paper, a novel shunt regulator architecture is proposed to achieve the genuine characteristic of a shunt regulator with small quiescent current. The proposed shunt regulator transient response is 3.98µsec over full load current rising step and it is at least 3.5 times faster than series regulator. PSR characteristic of the proposed shunt regulator shows -22.4dB up to 200kHz.