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TCA6408A-Q1: Default output state

Part Number: TCA6408A-Q1
Other Parts Discussed in Thread: TCA6408A

Dear Team,

My customer is working on TCA6408AQPWRQ1 to use this device on their design, but they realized that the outputs are pulled high in power up and stay at this state until the SW takes over the control. Is there a way to keep the outputs at low? or do we have version with active low outputs?

Best Regards,


  • Hi Caglar,

    The P-ports for TCA6408A will initially be configured as inputs with high-impedance output drivers (default value of the Configuration Register). The output driver will only become active and reflect the value of the Output Register once that pin is configured as an output using the Configuration Register. Until then, the value of the pin will be determined by external pull-up/down resistors and leakage paths.

    Is there another device/component that could be provide a leakage path from these lines to Vcc before the I/O expander is configured?

    Eric Schott