An NMOS Low Dropout Voltage Regulator with Switched Floating Capacitor Gate Overdrive

This paper presents a 1.5 V 50 mA low dropout voltage (LDO) regulator using an NMOS transistor as the output pass element. Continuous time operation of the LDO is achieved using a new switched floating capacitor scheme that raises the gate voltage of the pass element. The regulator has a 0.1 V dropout at a 50 mA load and is stable for a wide load current range with loading capacitances up to 100 pF. The output variation when a full load step is applied is 35 mV and the recovery time is below 0.6 mu s. It is designed in a 0.13 mu m CMOS process with an area of 0.018 mm(2) and does not require any external component.