Low Dropout (LDO) Voltage Regulators are the linear regulators which drives upon a very small differential voltage. The main components of the Low dropout voltage regulators are Error amplifier, Pass device, voltage reference source and Voltage divider network. The low dropout voltage regulator uses a variable input to give a steady, constantly controlled, low-noise DC output voltage. This is a linear voltage regulator that includes a small voltage drop among the input as well as the output that works even when the output voltage is extremely close to the input voltage. The Error amplifier circuit which is one of the components in Low dropout voltage regulator is designed in the standard 180nm CMOS technology, with supply voltage of 1.6V, the gain of the error amplifier is 74db, Band-gap reference circuit is implemented to produce stable reference voltage which is independent of temperature variations. The bandgap reference voltage circuit gives the output voltage of 1.2V. The low dropout voltage regulator produces constant output voltage of 1.8V for the input voltage range 2.1V to 3.5V and it provides constant output voltage for load variations.