I have a design where the enable pin of this part is connected to ground (always enabled) and Vcc = 3.3V. The output is pulled up with a 5.6k resistor to 5V.
I see 3.3V on the output pin, even with the pullup.
Possible explanations:
The 3.3 V power supply is sinking current through a body diode in the part
If there's no body diode involved, the part's output can't sink current and the output is at logic 1.
Questions:
Am I on the right track with the current-sink ideas?
We're seeing a lot of noise on the 3.3V at the ouput, enough to dip into the logic '0' range for 3.3V logic. Is this arrangement especially susceptible to noise?
Thanks,
Jeff
