A fast transient output-capacitor-free low-dropout regulator with class-AB control stage

An output-capacitor-free (OCF) low-dropout regulator (LDR) with a class-AB control stage is presented. Due to the use of the class-AB control stage, the proposed design eliminates the need of an additional transient boosting circuitry while maintaining good transient performance. The proposed OCF LDR is simulated in 130nm CMOS technology. It consumes a quiescent current of 5μA, and provides an output current of 100mA with a dropout voltage of lower than 200mV at a supply voltage that ranges from 1.2V to 0.75V. The recovery time is less than 4μs and the output voltage spike is less than 23mV.