SN74AXC4T774: DIR pin

Vibhu Vanjari

Genius 11900 points

Hello,

I am using the SN74AXC4T774PWR part, I would like to confirm that I can connect the DIR pins directly to the VCCA/GND, without using any pullup/pulldown resistor.

Thanks,

Vibhu

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 327650 points

The DIR pins are high-impedance CMOS inputs, so an additional resistor has no effect (unless you intend to exceed the V_I absolute maximum rating).

0 ShreyasRao over 6 years ago

TI__Guru 64400 points

As Clemens suggested, it can be directly connected to gnd or Vcc without pullup/down resistor.

Please let me know the application if available.

0 Vibhu Vanjari over 6 years ago in reply to ShreyasRao

TI__Genius 11900 points

Hello Shreyas,

This is for an Ethernet switch board. If using a pullup/pulldown, would a 10k be okay? From my understanding the value doesn't matter because the internal resistor is of a higher order.

Thanks,

Vibhu

0 ShreyasRao over 6 years ago in reply to Vibhu Vanjari

TI__Guru 64400 points

Thank you for the information.

yes, 10k is fine.

The FAQ below answers your question on DIR pin.

Logic

Logic forum

SN74AXC4T774: DIR pin