Double-ring protection low drop out (LDO) linear voltage regulator

Abstract

The invention discloses a double-ring protection low drop out (LDO) linear voltage regulator comprising the following elements: an error amplifier used for switching dual-end input into single-end output, thus providing high output gain; an over-current protection circuit used for comparing output voltage with peak voltage, and using a feedback circuit to control a power tube, thus realizing over-current protection function; the power tube realized by a PMOS transistor common-source amplifier structure and used for providing sufficient gain for the LDO loop, and ensuring the LDO drop out voltage is the PMOS pipe leakage source voltage; a unit gain frequency compensation network used for generating zero point resistance. The conduction resistance of the PMOS pipe critical work point can be reduced to drop voltage, thus providing over-current protection effect, and the error amplifier can normally work; good stability is provided; the double-ring protection low drop out (LDO) linear voltage regulator has low input-output voltage difference, can stably work when voltage and temperature change, and has the over-current protection auxiliary function.

Description

technical field [0001] The invention belongs to the technical field of electricity, in particular to a double-ring protection low-dropout LDO linear voltage regulator. Background technique [0002] The design technology of the linear voltage regulator is relatively mature at present, and there are a large number of integrated linear voltage regulator module circuits, which make the power supply circuit of the linear voltage regulator more concise and more convenient to use. The power tube of the linear regulator works in a linear amplification state. In order to ensure that the output voltage has a sufficient stable range, there must be a certain margin of voltage drop on the power tube, which makes the power consumption of the entire linear regulator relatively large, and the working The efficiency is low. In order to reduce the power consumption of the linear regulator and improve its working efficiency, a low-dropout linear regulator (LDO) has emerged. In the early LDO c...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a double-ring protection low-dropout LDO linear regulator, which aims to solve the problem that the traditional compensation method mostly uses the ESR parasitic resistance on the capacitor to generate an external zero point for frequency compensation.

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