Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 33 subscribers
  • Views 241 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

PCF8575C: Pulse signal recognition

Yongki Jeong1
Intellectual 525 points
Part Number: PCF8575C
Other Parts Discussed in Thread: BQ25601, PCF8575, SN74LVC2G74, TCA8418

Hi Ti Team

I plan to use several 'BQ25601(4EA~)' by connecting them to the MCU.
MCU needs to read the INT signal of BQ25601 through PCF8575,
Can MCU recognize pulse signal through PCF8575?

Sincerely

Jeong

  • +1
    Guru 280000 points

    The PCF will activate its interrupt output when any input pin changes, but it will deactive the interrupt when the input changes back. So you can recognize the signal only when you read the input port of the PCF quickly enough.

    If you cannot guarantee that you have completed the read inside of 256 µs, then you have to store the interrupt state in a flip-flop (e.g., SN74LVC2G74) and to clear it manually.

  • 0 in reply to Clemens Ladisch
    TI__Genius 15345 points

    Hi Jeong,

    Just to add onto what Clemens said, we don't have any I/O expanders currently that latch the INT pin when an input port changes value. The TCA8418 does but it is more of a keypad scanner.

    Best,

    Chris