A Fast-Response NMOS-LDO Voltage Regulator without on-chip Compensated Capacitor

A NMOS type low-dropout (NMOS-LDO) voltage regulator with fast transient response is proposed in this paper. The NMOS-LDO is a dual-loop circuit whose inner loop can increase the regulating speed of the output voltage of the proposed LDO, and a NPN is adapted to move the dominate pole from the output point to the inner of the LDO chip without any miller capacitor or other onchip compensated capacitor. In 0.35μm CMOS process, the simulation results of the proposed LDO show that the rise time and fall time of LDO are about 2.11μs and 4.26μs for 10μA ~10mA step change of load current.