Capacitor Less Voltage Regulator with Split Drive Error Amplifier for Segmented Pass Transistors

摘要

In this paper a capacitor-less low drop out regulator that employs split pass transistor driven by suitable error amplifiers for improved transient response. One of the segmented pass transistors is sized to meet the fast load transients while the overall pass transistor addresses thedropout voltage. The error amplifiers are designed to impart the requisite drive quickly to the respective pass transistors to improve transient response while conserving the quiescent current. The regulator is designed using 180 nm technology and exhibits undershoot of 87.52 mV and an overshootof 174.4 mV for the load current variations of rise and fall time of 500 ns. It provides a regulated output voltage of 1.6 V with a dropout voltage of 200 mV by consuming a quiescent current of 40 μ A and is useful for System on Chip (SoC) applications.