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Question about pullup value on PCA9543ADR

Lee Draper
Prodigy 110 points
Other Parts Discussed in Thread: PCA9543A, TCA9543A

The data sheet recommends pulling the INT# output (pin 11) high to VDPUM, the master I2C reference voltage, which in our case is 3.3V.   What is the range of pull-up resistors that are acceptable for this purpose?  Would anything between 1K and 100K work?

  • 0
    TI__Mastermind 30260 points

    First of all, please consider using the TCA9543A as a replacement for the PCA9543A where possible. However, for now the TCA9543A is only available in the larger, PW (TSSOP) package.

    The answer to this question depends on the needs of your application.

    If this is a portable application, you may want to use a 100kOhm resistor to ensure less current is burned through the resistor.

    On ther other hand, if this application expects interrupts to occur very frequently, then using a 1kOhm resistor may be desirable, because the ramp rate of the /INT pin will be faster.