SN74LXC8T245-Q1: Simulation of Output-Pins - Ringing

Michael Rauls

Part Number: SN74LXC8T245-Q1
Other Parts Discussed in Thread: TINA-TI

Hello,

in our new design I use SN74LXC8T245QPWRQ1
for voltage translation 3.3V -> 5V. The circuit drives an external component (no design of our own).
The external component has parallel 16 bit interface, altogether there are 3 IC working in parallel to handle the bus.

There is heavy ringing on the output lines, I would try to limit the output driving strength.
Simulating the situation would help.

The question is: How can I make use of the provided IBIS model "SN74LXC8T245-Q1.ibs" (delivered in scem783a.zip)

Is it possible to import the IBIS file into TINA-TI V9 (9.3.200.277 SF-TI)?

Other options to see transient response of output pins?

Thank you & greetings
michael

11 months ago

0 Michael Ikwuyum 11 months ago

TI__Mastermind 26080 points

Hi Michael,

Unfortunately, IBIS model contains only the behavior of the I/O pins and not that of the actual logic. Hence, not feasible to convert into TINA.

However, you can also simulate the IBIS for the output. You may also see https://www.ti.com/lit/an/szza034/szza034.pdf?ts=1693480844750 further clarifying.

Schematics and waveforms can help double check if any other obvious gaps as sometimes not having bypass capacitors with noisy supplies can result to ringing.

You may also see [FAQ] What happens when I connect a logic device's output to a 50 ohm transmission line? if related to transmission line effects as limiting the output drive with series resistors helps, thanks.

Best Regards,

Michael.

Logic

Logic forum

SN74LXC8T245-Q1: Simulation of Output-Pins - Ringing