An Implementation of External Capacitor-less Low-DropOut Voltage Regulator in 45nm Technology with Output Voltage Ranging from 0.4V-1.2V

Low-DropOut (LDO) regulators are one of the most essential and critical analog blocks in power management of System-on-Chip (SoC) design. In this work, we present an external capacitor-less LDO voltage regulator design implemented in 45nm technology. The proposed design eliminates the resistive feedback network with a transistor which allows more control over output voltage and improve the transient response and PSRR. The design consists of Error Amplifier (EA), one common-source (CS) stage, one buffer stage and 2 pass transistors which offers a wide range of output voltage ranging from 0.4V-1.2V with an input voltage of 1.8V. The design also ensures low power operation with 7.824uA quiescent current. Furthermore, the design incurs minimum area of 0.0149mm2and voltage overhead of 25mV(max) along with a stable output voltage with less than 1mV ripple. The schematic and layout designs are implemented and simulated in Cadence Virtuoso using 45nm bulk CMOS process.