Power Regulator, also called Voltage Regulator, is an on-chip device which provides suitable power supply for the core from an external high voltage power supply. It is very convenient for a user to supply the chip with only one voltage although the whole chip needs two types of different voltage. Present project is a regulator that generates 1.8v voltage from 3.3v power supply. Based on GSMC 0.18um 3.3v process, it can provide two maximum currents of 60mA and 240mA separately.