I am using 4 ADM1176 one for +3V3, one for +5V and two for +12V
If I use +3V3 supply voltage for all of then or a combination of +3V3V and +5V for all of the, everything is working fine.
when I move to of them to +12V they disappears on the I2C bus.
It is the same set up, same IC, just the voltage there is change.
Any suggestion to why its not working