Switching stabilized voltage power supply and its method for stabilizing voltage

Abstract

The invention provides a switch voltage-stabilized power supply. The switch regulated power supply comprises a switch part, a sampling part, a feedback comparison control part, a pulse-width modulation (PWM) control signal generation and amplification part, a constant current source control part and an output filter part, wherein the sampling part is used for bearing partial current output by the output filter part so as to acquire feedback voltage; the constant current source control part is used for controlling the current which flows through the sampling part; the feedback comparison control part is used for comparing the feedback voltage with a reference voltage so as to generate small signal pulse signals; the PWM control signal generation and amplification part is used for modulating and amplifying the small signal pulse signals so as to acquire PWM control signals; the switch part is used for subjecting the input voltage to pulse width modulation under the control of the PWM control signals so as to supply the voltage to the output filter part; and the output filter part is used for filtering the voltage after the pulse width modulation and outputting the voltage. The invention also provides a voltage stabilizing method for the switch voltage-stabilized power supply. According to the switch voltage-stabilized power supply and the voltage stabilizing method, output voltage ripples are reduced.

Description

Technical field [0001] The present invention relates to the technical field of circuits, in particular to a switching stabilized power supply and a stabilized method thereof. Background technique [0002] The structure of the switching stabilized power supply based on the hysteresis mode is usually: the final output terminal of the stabilized power supply is fed back to the feedback control terminal of the power control chip through a resistor divider to form a control loop to stabilize the actual regulated output required. [0003] The structure of the entire control loop is as follows figure 1 As shown, the transistor Q1 for switching is mainly used, the power chip for outputting PWM (Pulse Width Modulation) switching pulses, the inductor L1 and capacitor C2 for filtering and stabilizing the back-end output are used. Voltage divider resistors R1, R2, etc. for sampling feedback. The control chip provides a hysteresis comparison voltage to ensure that the entire control loop does ...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims to provide a switching regulated power supply and its voltage stabilizing method to solve the problem that the output voltage ripple of the switching regulated power supply in the prior art will increase with the increase of the output voltage

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