SN74LVC257A: A_L/B direction line floating

Renan Santos Adriano

Part Number: SN74LVC257A

Hi Team,

My Customer has an old design using a SN74LVC257APW. The A_L/B direction line is floating. Does the part have a pull-down or pull up internally? Is it OK to float this signal? Does the part always behave the same way?

We know that unused input pins must not be left floating and must be tied to GND or VCC, whichever makes more sense or is more convenient or depends on the function of the device.

Looking forward to your input.

Regards,
_Renan

over 5 years ago

0 Karan Kotadia over 5 years ago

TI__Genius 16735 points

Hi Renan,

Yes, you will need to apply a valid logic input on the A/B select pin. So tie it to either GND or Vcc.

I am curious as to how you are using the device with the select pin floating?

Thanks!

-Karan

Logic

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SN74LVC257A: A_L/B direction line floating