SN74LXCH8T245: Wide range of propagation delay

Carlo

Part Number: SN74LXCH8T245
Other Parts Discussed in Thread: SN74AXC8T245

Hi team,

Good day.

Our customer is interested in our new device SN74LXCH8T245, however, they have noticed in the switching characteristics that the propagation delay varies from 0.4 ns to 90 ns. They would like to know the reason why the propagation delay is so wide since they worried that it can affect the performance of their yield. Do we have a typical value for this parameter?

Regards,
Carlo

over 3 years ago

0 Chad Crosby over 3 years ago

TI__Expert 6680 points

Hi Carlo,

Let me see if I can get some supplemental data for you.

Thanks!

Chad Crosby

0 Chad Crosby over 3 years ago

TI__Expert 6680 points

Hi Carlo,

We're seeing around 27ns tpd for 25C on the bench, with anywhere from ~20ns to 40ns across temperature and 10% voltage tolerances. These values should be treated as supplemental to the datasheet, and not a guaranteed by TI. I would; however, expect these values to be tightened to look a bit more like the SN74AXC8T245.

Thanks!

Chad Crosby

0 Carlo over 3 years ago in reply to Chad Crosby

TI__Expert 7715 points

Hello Chad,

Thank you for measuring the value on the bench setup. Since the control pins of the SN74LXCH8T245 (DIR and OE) are referenced to VCCA, is the propagation delay for Vcca the same with DIR pin?

Regards,
Carlo

0 Chad Crosby over 3 years ago in reply to Carlo

TI__Expert 6680 points

Hi Carlo,

The values for the control pins are similar to the above. Again, I would expect these values to be tightened eventually.

Thanks!

Chad Crosby

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SN74LXCH8T245: Wide range of propagation delay