SN74AXC4T245: No power situation

Efi Ovadia48

Part Number: SN74AXC4T245

Hi,

Regarding the SN74AXC4T245 - can I assume that if the part is not powered from both sides - the input and output signals are high-z?

Thank you,

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 242930 points

Section 8.3.4 of the datasheet says:

The inputs and outputs for this device enter a high-impedance state when either supply is <100mV.

0 Michael J Schultis over 3 years ago in reply to Clemens Ladisch

TI__Mastermind 24485 points

Thank you Clemens!

Hello Efi,

Clemens is correct, and the key here is that one of the supplies is actually connected and in a known state below 100mV.

If both supplies are "floating" then there is a chance that some charge could couple onto the line, causing the device to be enabled, in which case some of the ports may no longer be in Hi-Z.

Its a matter of making sure that the ports are at a known voltage.

Best,
Michael

0 Efi Ovadia48 over 3 years ago in reply to Michael J Schultis

Intellectual 285 points

Thank you both,

It helps a lot,

Efi

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SN74AXC4T245: No power situation