LSF0102: the device can't run 1V to 3.3V 8Mhz on I3C

Jim Tsai

Expert 4470 points

Part Number: LSF0102
Other Parts Discussed in Thread: TCA39306

Hi,

My customer use LSF0102 to run I3C but can't run the speed to 8Mhz.

They would like to know whether TCA39306 has better performance on speed?

Could you help to check whether TCA39306 can drop in replace LSF0102 for I3C application?

I checked the spec of LSF0102 and TCA39306, seems like they should be pin to pin compatible, could you also confirm it? Any BOM change need?

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 316690 points

Replacing the LSF with the TCA39306 will not make any difference.

The only way to get faster rising edges is to make the pull-up resistors stronger. But it's possible that the 1 V device does not have enough drive strength for that.

0 Jim Tsai over 3 years ago in reply to Clemens Ladisch

TI__Expert 4470 points

Hi Ladisch,

Could you help to provide the formula or equation to calculate the value or a training video or something?

0 Clemens Ladisch over 3 years ago in reply to Jim Tsai

Guru 316690 points

See [FAQ] How do the LSF translators work?

But the speed depends on the parasitic capacitances of your board, so the only pratical way of sizing the pull-up resistors is to check the waveform with an oscilloscope.