Switching power supply control method and device

Abstract

The invention relates to a switching power supply control method and a switching power supply control device. The method comprises the following steps of: a, acquiring an output voltage sampling signal, and generating a voltage compensation signal based on a difference between an output voltage reference and the output voltage sampling signal; b, acquiring an input voltage sampling signal, and dividing the voltage compensation signal by the input voltage sampling signal to generate a first sampling signal reference; c, acquiring a first sampling signal, and generating a duty ratio based on the difference between the first sampling signal reference and the first sampling signal; and d, generating a control signal of a main circuit switch based on the duty ratio. Through the switching power supply control method and the switching power supply control device of the invention, when the power supply hops, a voltage compensator can make the first sampling signal reference reach a new stable value in real time without adjustment, so input power is equal to output power and an output voltage stays the same.

Description

Technical field [0001] The invention relates to a power supply, and more specifically, to a control method and device of a switching power supply. Background technique [0002] Switching power supply is a voltage conversion circuit, mainly used for step-up and step-down, and is widely used in modern electronic products. A switching power supply generally includes a main circuit and a control circuit. The control circuit samples the main circuit signal, adopts a certain control method and device, and converts it into a control signal to control the operation of the main circuit. [0003] The prior art switching power supply control circuit is generally as figure 1 with figure 2 Shown. figure 1 It is a schematic diagram of the control circuit of a switching power supply in the prior art; the control method adopted is that the difference between the output voltage reference and the output voltage sampling signal is generated by a voltage compensator to generate the first sampling si...

AI Technical Summary

Problems solved by technology

When the source jumps, the sampling signal of the effective value of the input voltage remains almost unchanged or the speed of change is slow. At the same time, the adjustment speed of the voltage compensator is slow, which causes the first sampling signal reference to be too large or too small when the source jumps. It takes a long time to reach a new stable value

Before reaching the new stable value, the input power is too large or too small due to its large or small value, which causes the output voltage to overshoot or drop

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