A capless NMOS low-dropout regulator with 15 ns transient response time

In this paper, a fast-transient capless NMOS low-dropout regulator (LDO) with low power consumption is proposed. The capacitor multiplier and Super Class-AB operational transconductance amplifier (OTA) with local common mode feedback structure (LCMFB) is employed in the proposed LDO, which not only consumes a small quiescent current but also greatly improves the transient response by increasing the loop bandwidth and charging/discharging current at the gate of the power transistor. Meanwhile, excellent line/load regulation is also achieved by the proposed LDO. The proposed capless LDO was implemented in 0.18 μm CMOS process and the post-layout simulation results show that the transient response of recovery time is only 15 ns, low quiescent current is 11 μA, and line regulation and load regulation are 0.61 mV/V and 7.58 μV/mA respectively.