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TCA8418: Varying debounce delay

Karmugilan Sudandaranathan
Prodigy 20 points
Part Number: TCA8418

Hello everyone,currently I am working on TCA8418 keypad controller.I am having trouble varying the debounce delay of TCA8418. I could find the minimum and maximum debounce delays mentioned in the datasheet as 50 uS and 60 mS respectively,but I could not find much informations on varying the debounce delay.Kindly someone help me find a solution for the issue.With regard Karmugilan.

  • 0
    TI__Genius 16510 points
    Hello Karmugilan,

    The TCA8418 has 2 different debounce circuits, which are used depending on the mode. They are not adjustable.

    The 50 us debounce is used when 1) debounce disable is set to 0 and 2) the pin in question is not used in a keypad matrix mode. This will debounce any incoming signal for 50 us. This is also the only debounce available when not in keypad matrix mode:

    When a pin is used in a keypad matrix mode, a 50 ms debounce is always used (regardless of the state of the debounce_disable registers) to detect key presses. This cannot be enabled or disabled, nor used on any mode other than matrix keypad mode.
  • 0 in reply to Jonathan Valdez
    Prodigy 20 points
    Thank You for your timely reply Mr. Jon.The answer was very helpful.