I want to power the IC with 3.3V.
The input I2C wil be 'pulled-up' to 5V.
The output I2C will be 'pulled-up' to 2.5V, 3.3V, and 5V.
Is there any problem with this setup?
Hello Martin,
You might have a problem depending on the temperature you are operating and what your pull up strength is. If you look at the Vpass vs Vcc plot you see that at 3.3V you could have problems with the maximum temp. You could put Vcc at 2.5V and you should be fine. The only concern is that at 2.5V the Vgs of the pass fet is not as large so pass FET resistance will be a bit larger which could affect VOL.
Do you know the capacitances on each bus, the pull up resistor used, data rate, and worst case VIL of all devices on the bus? Schematics would be helpful in assessing if you guys will have problems.
Sincerely,
-Francis Houde
