Low-dropout linear voltage regulator circuit and system

Abstract

The invention provides a low-dropout linear voltage regulator circuit. The circuit comprises a power supply end, an inner ring control module, an outer ring control module, a reference voltage end, a feedback module, an output end and an earthing end, wherein the inner ring control module and the feedback module form a quick access with high bandwidth and low gain; the outer ring control module and the feedback module form a slow access with high gain and low bandwidth; the outer ring control module comprises a first operational amplifier, a first field-effect transistor connected with the first operational amplifier, a capacitor connected with the first operational amplifier and the first field-effect transistor, as well as a first resistor connected with the first field-effect transistor; the inner ring control module comprises a second operational amplifier, as well as a second field-effect transistor connected with the second operational amplifier; and the feedback module comprises a second resistor, a third resistor connected with the second resistor, as well as a fourth resistor connected with the third resistor. The invention also provides a low-dropout linear voltage regulator system. The circuit and the system have high-accuracy output and can realize quick response.

Description

technical field [0001] The invention relates to a voltage stabilizing circuit and system, in particular to a low-dropout linear voltage stabilizing circuit and system with high-precision output and fast response. Background technique [0002] LDO (low dropout regulator) is a low-dropout linear regulator, which has the advantages of low noise and easy integration, and is widely used in electronic systems. [0003] see figure 1 , figure 1 It is an existing LDO circuit structure, wherein CMP is a single-stage operational amplifier, MP is a field effect transistor, resistor R11 and resistor R22 form a feedback circuit, and VREF' is a reference voltage. Since the entire loop must have a high gain to ensure a high-precision output value, and high gain and high bandwidth usually cannot be satisfied at the same time, so the existing LDO circuit structure often has the characteristics of low bandwidth, that is, it is difficult to achieve fast response. Therefore, when the power su...

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Problems solved by technology

Since the entire loop must have a high gain to ensure a high-precision output value, and high gain and high bandwidth usually cannot be satisfied at the same time, so the existing LDO circuit structure often has the characteristics of low bandwidth, that is, it is difficult to achieve fast response. Therefore, when the power supply voltage VDD' or the load changes rapidly, the output terminal VOUT' will cause a large overshoot or drop, and it will take a long time to return to the normal output value, which will greatly reduce the system performance. even make the system not work

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