TCA9548A: TCA9548A unused pin

Wu Rain

Prodigy 130 points

Part Number: TCA9548A

Hi Sir

How do I do about the unused pin of downstream I2C pairs ? tie to VCC or GND? or oull up to Vcc?

Thanks

Rain

over 6 years ago

0 Miguel Robertson over 6 years ago

TI__Guru 62920 points

Hi Rain,

The best option would be to pull up the ports to VCC via a resistance. This way I2C communication can still occur properly if any of the unused channels become inadvertently enabled. As long as a channel is disabled, though, it will remain high-impedance and so the voltage on it is not critical (neither a high nor low level on it would cause issues).

Max

0 Wu Rain over 6 years ago in reply to Miguel Robertson

Prodigy 130 points

Hi Max
For PCB saving,So as long as I set the unused pin disabled by control register and only enable designated channel that may be not needed pull up register,right ?

0 Miguel Robertson over 6 years ago in reply to Wu Rain

TI__Guru 62920 points

Rain,

Yes, you are correct.

Regards,
Max

0 Wu Rain over 6 years ago in reply to Miguel Robertson

Prodigy 130 points

Thanks Max

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TCA9548A: TCA9548A unused pin