Hi everyone
I'm having trouble with understanding how this circuit can be bi-directional:
.. as I can't quite figure out, why a signal on the 5V side would have effect on the 3.3V side.
This means that I'm not sure if I would be able to use this for my project, which requires me to sink a 5V level with a 3.3V (non 5V tolerant) device. Would that be possible with this simple setup?
Regards Sticky
When the 3.3v logic line is low the voltage from gate to source is 3.3v which turns the switch on causing the 5v logic line to be low or 0 volts.
When the 3.3vlogic line is high the souce is also at 3.3 volts, so the gate to source voltage is 0, so the switch is off and the 5V logic line is high (pulled up to 5 volts)
Stickybit2000:
.. as I can't quite figure out, why a signal on the 5V side would have effect on the 3.3V side.
The 3.3volt line can be pulled low through the body diode of the fet.
Leo..
