A low voltage difference voltage stabilizer circuit with an auxiliary circuit

Abstract

The invention provides a low voltage difference voltage stabilizer circuit with an auxiliary circuit. The low voltage difference voltage stabilizer circuit comprises a low voltage difference voltage stabilizer, a sampling circuit, a mirroring circuit and a current source circuit. The low voltage difference voltage stabilizer comprises a power MOS transistor; the drain electrode of the power MOS transistor outputs voltage stabilizing voltage; the sampling circuit is connected with the gate electrode of the power MOS transistor and sampling the current of the power MOS transistor; the current of the sampling circuit and the current of the power MOS transistor have a first proportion relationship; the mirroring circuit is connected with the sampling circuit and the current source circuit and makes the current of the sampling circuit and the current of the current source circuit have a second proportion relationship; the current value, which is obtained when the voltage stabilizing voltage is greater than a preset reference voltage, of the current source circuit is greater than the current value, which is obtained when the voltage stabilizing voltage is less than the preset reference voltage. The low voltage difference voltage stabilizer circuit with an auxiliary circuit can fulfill the functions of short circuit protection, soft start and current limiting.

Description

technical field [0001] The invention relates to the field of circuits, in particular to a low-dropout regulator circuit with an auxiliary circuit. Background technique [0002] In electronic equipment, the power supply voltage may usually vary within a large range. For example, a lithium-ion battery in a portable device can provide a voltage of 4.2 volts when it is fully charged, and can only provide a voltage of 2.3 volts after discharge. The range of variation is very large. Big. The working circuit of electronic equipment usually requires a stable power supply voltage, so at present, a low dropout regulator (LDO: Low Dropout Regulator) circuit is usually added to the output of the power supply. Since the low dropout regulator has a set voltage regulation, its First, the actual power supply voltage is converted to the set regulated voltage, and then the converted regulated voltage is provided to the working circuit, thus ensuring that when the power supply voltage of elec...

AI Technical Summary

Problems solved by technology

[0006] The problem solved by the present invention is that the performance of the low dropout voltage regulator circuit in the prior art is not good

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