What is debounce?
- Thread starter dthx
- Start date
It's when all the air goes out of the basketball. Just kidding...
When a mechanical switch is used as a data input, the contacts "bounce" upon contacting and un-contacting. This can cause havoc in digital systems. So either a network is used to insure only one of the bounces is sensed by the logic, or a software process is used to capture the correct logical level and ignore the bounces.
When a mechanical switch is used as a data input, the contacts "bounce" upon contacting and un-contacting. This can cause havoc in digital systems. So either a network is used to insure only one of the bounces is sensed by the logic, or a software process is used to capture the correct logical level and ignore the bounces.
When a mechanical switch closes or opens, the contacts vibrate and open/close dozens of times in reality. Debounce means some way to electronically filter out the bounce to make a circuit function correctly.
More details to follow by other members, usually capacitor filters or software delays.
More details to follow by other members, usually capacitor filters or software delays.
Last edited:
Tubeguy's link has an additional link to ONSemiconductor DATASHEET (MC14490) that describes debounce as: "the elimination of extraneous level changes that result when interfacing with mechanical contacts."
unfortunately, that is how they describe the chip's funnction - without ever saying the word, "debounce". I would never have thought of looking for a "bounce eliminator circuit". No wonder I have never heard of the chip nor seen it used in a circuit. Nobody knows it exists.
unfortunately, that is how they describe the chip's funnction - without ever saying the word, "debounce". I would never have thought of looking for a "bounce eliminator circuit". No wonder I have never heard of the chip nor seen it used in a circuit. Nobody knows it exists.
Here are some results when I searching on google for debouncing.
Almost of time that I am using "debounce circuit" to search.
debounce - 398000 results.
debouncing - 145000 results.
debounce circuit - 165000 results.
debouncing circuit - 70200 results.
switch debounce - 193000 results.
switch debouncing - 78200 results.
bounce eliminator circuit - 673000 results.
Almost of time that I am using "debounce circuit" to search.
debounce - 398000 results.
debouncing - 145000 results.
debounce circuit - 165000 results.
debouncing circuit - 70200 results.
switch debounce - 193000 results.
switch debouncing - 78200 results.
bounce eliminator circuit - 673000 results.
