LSF0108: VIO is 3.3V when VREFA is 1.8V

Luke Sun

Intellectual 1830 points

Part Number: LSF0108

Hi team,

When using LSF0108, customer has an application that one of the A port is using 3.3V signal, but not 1.8V signal.

Is it still OK when LSF0108 VrefA is 1.8V & VrefB is 3.3V?

If yes, does B side still need pull up resistor to 3.3V?

THanks!

over 7 years ago

0 Emrys Maier over 7 years ago

TI__Guru* 97066 points

Hi Luke,

I would recommend watching this video series on how the LSF translators work:Understanding the LSF Family of Bidirectional, Multi-Voltage Level Translators

Typically there isn't a problem with a voltage being higher than the reference, however you haven't given me enough information to be certain. I would need to see a schematic showing all involved devices, as well as any pull-up/pull-down resistors.

Logic

Logic forum

LSF0108: VIO is 3.3V when VREFA is 1.8V