SN74AUP1T32: Output state with an Open Input.

Scott Morrill

Part Number: SN74AUP1T32

If either input A or B, pins 1 and 2 respectively, are left open can the input be considered a logic 0 at that input. In other words, if A input is low at 0V and B is left open can I be sure the output will go to logic low(0Volts)?

over 1 year ago

+1 Clemens Ladisch over 1 year ago

Guru 285560 points

No. A floating input might be read as low, or high, or oscillating. And it will increase power consumption, and might damage the device. See [FAQ] How does a slow or floating input affect a CMOS device?

+1 Scott Morrill over 1 year ago in reply to Clemens Ladisch

Prodigy 70 points

Okay thank you.

I'm doing a safety circuit where I have to consider open traces in circuit board(PCB) as a failure mode. I need a similar device that would have internal pull-down resistors or defined state with open inputs, any ideas?

0 Clemens Ladisch over 1 year ago in reply to Scott Morrill

Guru 285560 points

TXU translators have internal pull-down resistors, but they do not implement logic functions.

0 Scott Morrill over 1 year ago in reply to Clemens Ladisch

Prodigy 70 points

thanks I'll take a look

Logic

Logic forum

SN74AUP1T32: Output state with an Open Input.