LSF0108: slew rate too slow issue

user4979899

Part Number: LSF0108
Other Parts Discussed in Thread: SN74AVC2T45, SN74AVC4T774, SN74AXC8T245

Hi Sir,

Create a new e2e questions to continue discussion from below e2e link,

(e2e.ti.com/.../803940)

And now, my customer can fix the rising time slow issue by using smaller pull up resistor (from 1K to 220 ohm) on LSF0108.

Now they’re considering to change solution to address this issue directly. and they just found AVC4T774 can fix it without external pull up resistor tuning.

So could you please help to check if this is the right solution to use? Thanks

http://www.ti.com/lit/ds/symlink/sn74avc4t774.pdf

In parallel, they also asking for 8 channels solution and below seems proper fit? Please help to check. Thank you

http://www.ti.com/lit/ds/symlink/sn74axc8t245.pdf

over 6 years ago

0 Clemens Ladisch over 6 years ago

Guru 317250 points

All the signals are unidirectional, so the SN74AVC4T774 would work fine. (Probably with something like the SN74AVC2T45 for the remaining two signals.)

The SN74AXC8T245 has two groups of four pins each, with one DIR pin per group, so it would not be enough for the five signals in the low-to-high direction.

0 user4979899 over 6 years ago in reply to Clemens Ladisch

TI__Expert 3080 points

Then do you have any suggestion on the 8 channel device?

0 Clemens Ladisch over 6 years ago in reply to user4979899

Guru 317250 points

There is no single device that can translate five signals up and one signal down (except for auto-direction-sensing devices like the LSF0108).

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LSF0108: slew rate too slow issue