Wide dynamic range and low voltage difference linear constant voltage regulator

Abstract

The invention provides a wide-dynamic range low-voltage difference linear voltage stabilizer which comprises a rail-to-rail error amplifier, a dynamic bias circuit, a driving element, a feedback circuit and a compensation circuit. The error amplifier is provided with a preset voltage input terminal and a feedback voltage input terminal. The output terminal of the error amplifier is connected with the input terminal of the dynamic bias circuit. The output terminal of the dynamic bias circuit is connected with the input terminal of the driving element. The driving output terminal of the driving element is connected with the feedback circuit. The feedback voltage is transmitted to the feedback voltage input terminal of the error amplifier. The driving element receives a signal from the dynamic bias circuit and controls an output voltage according to the signal. One end of the compensation circuit is connected with the output end of the driving element and the other end thereof is connected with the error amplifier. The rail-to-rail error amplifier widens the available range of the reference voltage and the output voltage of the linear voltage stabilizer. The dynamic bias circuit increases the transient response speed of the driving element and prolongs the battery life. The feedback circuit is arranged externally to facilitate the control of the output voltage.

Description

technical field [0001] The invention belongs to the technical field of voltage regulator circuits, in particular to a wide dynamic range low-dropout linear voltage regulator. 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, MP4s, 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. An LDO regulator is usually an error amplifier and a driver element connected in serie...

AI Technical Summary

Problems solved by technology

When the preset reference voltage at the input of the error amplifier is too large (Vsg is less than Vth), the transistor works in the cut-off region, resulting in the low dropout linear regulator not working properly

That is to say, the low-dropout linear regulator using the PMOS transistor as the input terminal of the error amplifier cannot be used in occasions where the power supply voltage required by electronic equipment is too high (close to the power supply voltage)

When the feedback circuit is full feedback, it is difficult to meet the low dropout characteristic requirements by using a PMOS transistor alone as the error amplifier of the low dropout voltage regulator.

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