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enter image description here

I'm using a n channel MOSFETa bidirectional level translator. The case when the body diode conducts the source end will be literally 0V or forward voltage of body diode, so the difference in voltage across gate to source will be enough to form a channel.

My question is: few seconds after the GPIO 1 pulls down, whether the channel between source to drain starts to conduct or not ?

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  • \$\begingroup\$ The picture doesn't look like one. \$\endgroup\$ – Andy aka Jan 8 at 13:35
  • \$\begingroup\$ yes it's not exact level translator, i have simplified it for the case i have mentioned. \$\endgroup\$ – Vignesh C Jan 8 at 13:40
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    \$\begingroup\$ The voltage at the source will never exceed ~ 0.6 V. What is the purpose of using a MOSFET like that? This circuit basically draws some current from the right VCC2P8 and it will draw slightly more current when the left VCC2P8 is present. I do not see how this circuit will do anything useful. \$\endgroup\$ – Bimpelrekkie Jan 8 at 13:41
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    \$\begingroup\$ Unless you are 100% convinced that simplifying the circuit doesn't change anything relevant, just don't simplify your circuit. I have seen plenty of questions here where the simplification removed relevant parts that were causing the actual issue or the parts that were removed were crucial to the operation of the circuit. If you have to ask when the MOSFET conducts etc. then usually you're not fully understanding the circuit and it will be better to include everything for clarity. \$\endgroup\$ – Bimpelrekkie Jan 8 at 13:47
  • \$\begingroup\$ i have simplified it because it is a open drain buffer, while the gpio at the drain side pulls down it is ideally a ground point that's why is mentioned like that, since my doubt is regarding whether the diode conducts or channel conducts i removed things which does not have any effect in my question. \$\endgroup\$ – Vignesh C Jan 8 at 13:56
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The body diode saves you in that scenario. Your source is pulled down to ~0.65V through the body diode. Assuming your gate threshold on the FET is under 2.15V, that will enable the channel which will immediately pull it down the rest of the way.

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