A low quiescent current high psrr low dropout linear voltage regulator circuit

Abstract

A low quiescent current, high PSRR, low-dropout linear regulator circuit. The circuit comprises an error amplifier (10), an adjusting component (20), a voltage dividing circuit (30), and a frequency band enhancing circuit (40). A drain electrode of the adjusting component (20) is connected to an input end of the voltage dividing circuit (30); a gate electrode of same is connected to an output end of the error amplifier (10). An output end of the voltage dividing circuit (30) is connected to an input end of the error amplifier (10). An end of the frequency band enhancing circuit (40) is connected to a substrate of the adjusting component (20). The frequency band enhancing circuit (40) forms a second path that runs from a power supply voltage end to an output end and is different from a first path that passes through the adjusting component (20). With one frequency band enhancing circuit (40) being provided in an existing low-dropout linear regulator, by generating an additional zero frequency, noise of a power supply voltage at a certain frequency point is eliminated, thus increasing the PSRR around the frequency.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a low quiescent current high PSRR low dropout linear regulator circuit. Background technique [0002] Low dropout linear regulator (LDO, Low Dropout Regulator) has the advantages of low output noise, simple circuit structure, small chip area occupied and small electrical ripple, etc., and is an important part of the power management circuit. The low dropout linear regulator circuit can provide low output ripple power supply and better power supply rejection ratio (PSRR, Power Supply Rejection Ratio, power supply rejection ratio) and lower noise performance for noise-sensitive circuits such as analog circuits and radio frequency circuits , which is widely used in handheld devices and portable electronic products. [0003] With the rapid development of integrated circuits, the operating frequency of chips continues to increase, and the PSRR performance of the low-dropout linear ...

AI Technical Summary

Problems solved by technology

Since the bandwidth of the low dropout linear regulator circuit is limited, and the PSRR decreases as the frequency increases, the high frequency noise outside the bandwidth of the low dropout linear regulator circuit cannot be attenuated by the low dropout linear regulator circuit itself, resulting in a constant decrease in PSRR, such as figure 2 shown

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