DC-DC decompression converter and ripple improving circuit

Abstract

The invention provides a DC-DC buck converter and a ripple improving circuit thereof. The DC-DC buck converter is used for converting the input voltage to the lower output voltage and comprises a switch for controlling the turning-on and the turning-off states of a path between the input voltage and the output voltage, a filter circuit for enabling the output voltage to trend to be stable, a comparison circuit for outputting a set signal according to the output voltage, a reset signal generating circuit for generating a reset signal and a trigger for controlling the starting and the closing states of the switch according to the set signal and the reset signal. The reset signal generating circuit comprises an oscillator, a capacitor which is externally connected to the oscillator, and the ripple improving circuit. The ripple improving circuit comprises a power supply input terminal for providing the voltage and a resistor with one end which is connected with the oscillator and the capacitor and the other end which is connected with the power supply input terminal. The invention is used for regulating the time for charging the capacitor, further adjusts the maximum duty cycle of thereset signal and improves the output ripple of the buck converter.

Description

technical field [0001] The invention relates to a DC-to-DC step-down converter and a ripple improvement circuit thereof, in particular to a DC-to-DC step-down converter capable of improving output ripple and a ripple improvement circuit thereof. Background technique [0002] Today's electronic products have higher and higher requirements for operating voltage, and some commonly used power supply voltages can no longer meet the requirements of many electronic products. In the current power supply design, more and more voltage conversion circuits are used. For example, when the power supply voltage is based on the central processing unit (CPU), DIMM (Dual Inline Memory Module, dual inline memory module), etc., it is often necessary to convert the input voltage of the power supply to an output voltage suitable for the load to make the load normal work. [0003] In a DC-to-DC step-down conversion circuit (BUCK circuit) that uses a combination of a comparator and an RS flip-flo...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a DC-to-DC step-down converter to solve the problem of high cost in the ripple reduction method of the DC-to-DC step-down conversion circuit in the prior art

[0010] Another object of the present invention is to provide a ripple improvement circuit to solve the problem of high cost in the ripple reduction method of DC to DC step-down conversion circuit in the prior art

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