Voltage stabilizer

Abstract

An embodiment of the invention discloses a voltage stabilizer. The voltage stabilizer comprises a voltage difference detection circuit, a power transistor, a first constant voltage modulation circuitand a second constant voltage modulation circuit, wherein the input end of the first constant voltage modulation circuit and the input end of the second voltage stabilization adjusting circuit are both electrically connected to the third end of the voltage difference detection circuit; the output end of the first constant voltage modulation circuit and the output end of the second constant voltagemodulation circuit are both electrically connected to the control end of the power transistor; the voltage difference detection circuit is used for detecting a voltage difference between a referencevoltage and the output end of the voltage stabilizer and outputting a detection signal; the first constant voltage modulation circuit and the second constant voltage modulation circuit are respectively connected to the power transistor to form a control loop; and the first constant voltage modulation circuit and the second constant voltage modulation circuit are used for jointly controlling the voltage of the control end of the power transistor according to the detection signal. The embodiment of the invention provides the voltage stabilizer, so that the output voltage of the voltage stabilizer can be quickly recovered to a stable value during overshoot and undershoot.

Description

technical field [0001] The invention relates to the technical field of voltage stabilizers, in particular to a voltage stabilizer. Background technique [0002] As the application specifications of various electronic products such as mobile phones and TVs are getting higher and higher, the specifications of the regulated power supply of the internal application circuit are also relatively improved, including instantaneous stable speed and pumping capacity. Low-dropout linear regulator (Low-Dropout regulator, LDO) is the most widely used due to its advantages of low dropout voltage and high efficiency. However, as the output load current changes suddenly, the output voltage of the low dropout linear regulator also changes suddenly, that is, the output voltage appears undershoot or overshoot. Voltage fluctuations such as large voltage overshoot or voltage undershoot often take a certain amount of time to return to a stable value, which not only affects the transient response ...

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