• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 117 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TCA6424A: About the TCA6424A

user6448843
Prodigy 160 points
Part Number: TCA6424A
Other Parts Discussed in Thread: TCAL6416, TCAL9539, TCA8418E

Tool/software:

The questions are as follows.

For example, when used as an input port and a switch circuit is connected to the port terminal to turn it on/off, does the TCA6424A include any chattering prevention (control)?

If so, please tell me specifically about its functions.

  • 0
    Guru 316470 points

    No, the I/O pins have plain CMOS inputs.

    If you are using the /INT signal to detect changes, and if you read the input port at the wrong time (when the input voltage happens to be back at the old value), then you will get another interrupt when the input voltage goes again to the new value.

  • +1
    TI__Mastermind 46888 points

    Hi User6448843,

    TCA6424A does not include switch chattering prevention. 

    If the input switches state (therefore causes an interrupt on /INT) and goes back to its original state, the interrupt will de-assert. 

    A device like TCAL9539 or TCAL6416 has latchable inputs where the switch state change is remembered until serviced (even if the input state returns back to original state). 

    Is it possible to use an external low pass filter for debouncing? 

    TCA8418E key pad scanner is also an option. This device has built in debounce circuitry + 10 byte FIFO. 

    Regards,

    Tyler