Jitter elimination circuit of key switch

Abstract

The invention provides a jitter elimination circuit for a key switch, and the circuit comprises a key K1, one end of which being connected with a power supply end; an anti-jitter delay unit, comprising a diode D1, a resistor R1 and a capacitor C1, the positive electrode end of the diode D1 being connected with the other end of the key K1, the negative electrode end of the diode D1 being connectedwith one end of the resistor R1, the other end of the resistor R1 being connected with one end of the capacitor C1 and a switching signal output end, and the other end of the capacitor C1 being connected with a grounding end; a quick discharge unit, the input end of the quick discharge unit being connected with one end of the resistor R1, the output end of the quick discharge unit being connectedwith the grounding end, and the control end of the quick discharge unit being connected with the other end of the key K1. When the key K1 is closed, the quick discharge unit is in a cut-off state, andwhen the key K1 is disconnected, the quick discharge unit is in an on state to quickly discharge the capacitor C1. The circuit has the advantages that: only the most basic electronic components are adopted, and the shake elimination processing of the switch key is realized by the simplest design. The device is simple in structure, low in cost and small in occupied circuit space.

Description

technical field [0001] The invention relates to the technical field of electronic product switches, in particular to a debounce circuit of a key switch. Background technique [0002] The key switch is a mechanical elastic switch. When the mechanical contact is disconnected and closed, due to the elastic effect of the mechanical contact, a key switch will not be connected immediately and stably when it is closed, and it will not be disconnected suddenly when it is turned off. . Therefore, there is a series of jitters at the moment of closing and opening. The jitter time is determined by the mechanical characteristics of the button, generally within 10ms. In order to ensure that the button is only responded to once on or off, the button must be debounced during the application process to avoid this kind of jitter. Causes erratic or erroneous responses. [0003] Existing technology mainly deals with the method of debounce of mechanical switch as follows: 1, software debounce...

AI Technical Summary

Problems solved by technology

The capacitor filter circuit is simple, but in practical applications, the effect of this method is often not very good. In addition, there is a problem with the discharge time of the capacitor. If the capacitor is too large, the switch will be triggered many times, which will easily lead to the wrong button of the switch; in monostable, trigger, etc. Debounce circuit, there are many components, the circuit structure is complex, the cost is high, and it takes up too much circuit space

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