DC/DC converter and its soft-start anti-overshoot method

Abstract

The application provides a DC / DC converter and a soft-start anti-overshoot method thereof. The DC / DC converter includes a DC / DC conversion circuit, an overshoot detection device, a pulse width modulation generator, an error amplifier, and an output of the error amplifier. The integrating circuit is connected to the terminal, wherein the integrating circuit is used to integrate the difference between the reference voltage and the output voltage of the DC / DC conversion circuit, and control the error amplifier to input the pulse width modulation generator. Amplify the magnitude of the voltage. The overshoot detection device acquires the working state parameters of the DC / DC converter, and controls the integrating circuit to discharge when the working state parameters of the DC / DC converter meet the requirements of the working state parameters. The application can effectively avoid the overshoot of the output voltage of the DC / DC converter at the end of the soft start, and has strong applicability.

Description

technical field [0001] The present application relates to the technical field of electronic circuits, and in particular, to a DC / DC converter and a soft-start anti-overshoot method thereof. Background technique [0002] A DC-DC converter (DC / DC converter) is a switching power supply device commonly used in electronic systems. Its main function is to convert a DC input voltage into a DC output voltage of another potential, so as to Meet the power supply requirements of the load-side electronic system. The DC / DC converter usually connects an integrating circuit at the output end of the error amplifier, which is used to compare the voltage difference between the input ends of the error amplifier (that is, the reference voltage and the output voltage of the DC / DC converter circuit) during the soft-start process. The voltage difference between the two) is integrated, that is, the voltage difference is accumulated, and the amplitude of the amplified voltage input by the error amp...

AI Technical Summary

Problems solved by technology

[0004] Since the output capacitor and the load at start-up vary greatly with different application scenarios, a single soft-start voltage slope will cause the system to have an overshoot risk in extreme cases

During the soft-start process, if the output capacitor is large, or the load current is large at the same time, the charging speed of the output capacitor may lag behind the soft-start voltage slope (that is, the soft-start voltage rise speed), which will cause the output of the integrating circuit to be too high or saturation

When the soft start ends (that is, the output voltage reaches the target voltage), it takes time for the integrating circuit to recover from the saturation state. During this process, the excessive energy in the inductor will be discharged to the output terminal, causing the output voltage to overshoot.

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