Broad output current scope low pressure difference linear manostat

Abstract

A low dropout linear voltage regulator with wide output current range and low pressure difference, comprises an error amplifier in the folding common source and common gate structure, a buffer circuit, a driving element, a feedback circuit, a load capacitance equivalent series resistance compensating circuit and a multistage Miller compensation circuit, wherein the buffer circuit changes the low frequency pole into a medium frequency pole and a high frequency pole; the large load capacitance of the load capacitance equivalent series resistance compensating circuit pushes the main pole to the low frequency, causing the gain crossover point to push inwards, and generating a medium frequency zero point for counteracting the medium frequency pole connected serially with the equivalent series resistance; the stride multilevel Miller compensation circuit generates a medium high frequency pole and a medium high frequency zero point slightly smaller than the medium high frequency pole for advancing the phase margin, thereby not only adding the unity gain bandwidth, but also saving considerable chip area. When the output current has a large change range, the structure provided by the invention generates wider unity gain bandwidth, provides the phase margin of greater than 85 degrees, ensures the stability of the system and advances the low pressure difference linear voltage stabilization performance.

Description

technical field

[0001] The invention relates to a low-dropout linear voltage stabilizer, in particular to a low-dropout linear voltage stabilizer with a wide output current range. Background technique

[0002] Current demands for high-performance power supply circuits have led to continued development of voltage regulator devices. Many low-voltage products, such as notebook computers, mobile phones, mobile DVDs, MP3s, cameras, and other devices that use mobile batteries, require the use of low-dropout (LDO) voltage regulators. These portable electronic devices usually require low voltage drop and small quiescent current to increase the power efficiency and life of the battery.

[0003] Typically, an LDO regulator provides a specific DC regulated voltage with a small voltage difference between the input and output. LDO regulators are often used to provide the required power to circuits. The schematic diagram of a typical low dropout voltage regulator is shown in figure 1 ...

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