SN74AXC8T245: Input signal limits when powered down and below -40C

Hi Steve,

Steve Widener said:

If the device is completely powered down (both Vcca and Vccb at 0V) is it acceptable to drive the IOs (i.e. have voltages present on signals connected to the IO pins)? Based on the abs max ratings I’d say yes but the description talks about partial (vs. full) powered application so it was a bit unclear.

This is okay. For a good way to tell, please see [FAQ] Can the input voltage (Vi) to my logic device be higher than the supply voltage (Vcc)?

Steve Widener said:

If the answer to #1 is yes, does this hold true at the storage temperature (specifically the cold end) of the device? For example, can I have a driver on the pin of one of these parts if it is powered down at -55°C?

It holds true for the specified -40 to 125 deg C similar to the recommended operating conditions per section 6.3.

Steve Widener said:

It doesn’t appear that there are any restrictions on the voltages of Vcca or Vccb beyond the limits correct? For example I can have Vcca=1.8V and Vccb=3.3V or Vcca=3.3V and Vccb=1.8V correct? I ask because I am using these (in part) for 3.3V<->1.8V level translation and have cases where the control signals need to be driven with 3.3V signals and others where they need to be driven with 1.8V signals.

Yes as VCCA and VCCB are both specified for 0.65V to 3.3V, thanks.

Best Regards,

Michael.

Hi Steve,

Unfortunately, we cannot guarantee outside the recommended operating condition as it could cause damage; similar to below, thanks. 

Best Regards,

Michael.