Controllable low voltage differential linear voltage stabilizing circuit for providing multi-output voltages

Abstract

The invention provides a low-dropout linear voltage regulator circuit which comprises a bandgap reference voltage circuit for generating reference voltage, an error amplifier, a driving cushion circuit, a power PMOS pipe and a feedback control circuit, wherein a negative end of the error amplifier receives reference voltage output by the bandgap reference voltage circuit; a positive end of the driving cushion circuit is connected with an output end of the error amplifier, and a negative end is connected with the output end; a source electrode of the power PMOS pipe receives power voltage of the low-dropout linear voltage regulator circuit, a drain electrode outputs the voltage, and a mesh electrode is connected to the output end of the driving cushion circuit; the feedback control circuitis connected between the positive end of the error amplifier and the drain electrode of the power PMOS pipe for the feedback of the output voltage. The low-dropout linear voltage regulator circuit realizes multiple voltage output by controlling feedback coefficients of a feedback resistive network by two signals. Moreover, a broadband operation transconductance amplification circuit with low power consumption and a unit gain structure is used for realizing the driving cushion circuit and the stable work of the high-load current circuit and rapid response performance can be ensured.

Description

technical field [0001] The invention relates to a low-dropout linear voltage stabilizing circuit, more specifically, to a controllable low-dropout linear voltage stabilizing circuit providing multiple output voltages. Background technique [0002] Low-dropout linear regulator circuit is an important branch of power integrated circuits. Compared with DC-DC (direct-direct-direct current) converters based on pulse width modulation (PWM) and pulse frequency modulation (PFM) principles, it has low cost , low noise and quiescent current, and the advantages of no inductor. In portable electronic products, a low-dropout linear regulator circuit is often used as the power supply of the system. [0003] figure 1 A schematic diagram showing a conventional low dropout linear voltage regulator circuit. Such as figure 1 As shown, the traditional low-dropout linear regulator circuit includes a reference voltage circuit, an error amplifier OTA1, a power PMOS transistor, and a feedback r...

AI Technical Summary

Problems solved by technology

However, the drive buffer stage of the source-follower structure will cause a level shift of the input and output voltages, resulting in the inability of the power PMOS transistor to be turned on or off.

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