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TCA9539-Q1: Input has signal before power on

Part Number: TCA9539-Q1

Dear team,

Due to SOC's power on sequence, we give 3.3V signal to 9539's input port before powering on 9539. Will this affect the normal operation of our chip?

Thanks & Best Regards,


  • Sherry,

    When VCC is off or VCC=GND, the ports are HI-Z. There are also diodes from the pin to VCC. So you won't see any leakage current on VCC unless you exceed the absolute maximum ratings.

    This shouldn't affect the normal operation of the device.