debounce circuit

Abstract

A debounce circuit includes a switching pulse generating circuit, a forward charging and discharging circuit, a reverse charging and discharging circuit, and a data selector. The debounce circuit is controlled by the output pulse through the data selector to select one of the forward charge and discharge circuit and the reverse charge and discharge circuit as the output pulse. The debounce circuit can automatically filter positive narrow pulses during negative wide pulses and negative narrow pulse interference during positive wide pulses, especially can filter continuous key or switch contact shaking narrow pulse interference signals; the positive narrow pulses that need to be filtered are the largest The width can be adjusted by changing the outflow drive current of the positive current driver or the size of the positive anti-interference capacitor; the maximum width of the negative narrow pulse that needs to be filtered can be adjusted by changing the outflow drive current of the reverse current driver or the reverse anti-interference capacitor to adjust the size. The debounce circuit can be applied in occasions where a circuit needs to be used to reliably eliminate the influence of key or switch pulse jitter.

Description

technical field [0001] The invention relates to a mechanical button or switch pulse signal processing circuit, in particular to a debounce circuit. Background technique [0002] In digital signal circuits, it is often required to output pulses when mechanical buttons or switches are pressed. When the mechanical key switch is pressed or released, the switch pulse will generate a jitter interference pulse due to the jitter of the contact. Using software to eliminate switch jitter needs to consume CPU working time, which greatly wastes system resources. When it is necessary to use a circuit to eliminate the influence of the jitter pulse of the key switch, the commonly used methods are RS flip-flop and RC filter circuit. When the RS trigger is used, the key switch is required to have a normally closed switch and a normally open switch at the same time, and its application is limited. When the RC filter circuit is used, when the jitter interference is continuous narrow pulse i...

AI Technical Summary

Problems solved by technology

When using the RS flip-flop, the key switch is required to have both a normally closed switch and a normally open switch, and its application is limited

When the RC filter circuit is used, when the jitter interference is continuous narrow pulse interference, the filter time constant needs to be increased to affect the rapid response capability of the circuit; or when there is continuous narrow pulse interference in the button circuit, the RC filter circuit has a DC memory effect. The previous narrow pulse will affect the filtering of the following narrow pulse

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