Low-dropout linear regulator

Abstract

The invention provides a low-dropout linear regulator. A turnover source voltage follower serves as an error amplification circuit in a loop and can induct changes of output voltage of a power output tube drain, when the output voltage changes, the error amplification circuit will provide corresponding error voltage to control a power tube grid driving circuit, the power tube grid driving circuit has the effect of increasing grid charging speed or discharging speed of a power output tube according to the error voltage to improve the converting speed of the power output tube, and the grid driving capacity of the power output tube is improved; as output resistance of the power tube grid driving circuit is extremely low, the power tube grid driving circuit can push a pole of a power output tube grid to a position with higher frequency, and a main pole of the loop is located at an output pole. The low-dropout linear regulator has fast transient response, stable loop bandwidth is provided by a simple compensation technology, and no ESR limit exists in off-chip capacitor selection.

Description

technical field [0001] The invention relates to the field of voltage regulator circuit design, in particular to a low-dropout linear voltage regulator. Background technique [0002] The low-dropout linear regulator is a key device in the existing SOC (System on Chip System on Chip) design, which is used to provide stable power to noise-sensitive modules. The transient response is an important dynamic parameter in the design of low-dropout linear regulators. The transient response of a low dropout linear regulator is related to different design parameters. Such as loop stability, loop bandwidth, and the slew rate of the power transistor gate. Especially in applications where the load current varies widely, the small bandwidth and slow slew rate limit the transient response. [0003] In fact, existing low dropout linear regulators are usually subject to a trade-off between loop stability, loop bandwidth, and power transistor gate slew rate. In order to improve loop stabili...

AI Technical Summary

Problems solved by technology

However, since the operating current of the adaptive gate drive circuit will change according to the change of the load current, this will cause the gate-source voltage of the flip voltage follower to also change, so that the output voltage will also change with the change of the load current.

In this way, the output range of the low-dropout linear regulator is very large, and the application is greatly limited.

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