Hello all,
I accidentally wired a p-mosfet with power at the drain, and default same voltage at the gate. If the power we're at the source I would expect the led load to be normally off when the gate is high, and on when the gate is pulled low. Right now the led is normally on. I thought this could be because the resulting Vgs is less than zero, but I am wondering why the drain-source is conducting. Since it is conducting, is the body diode not connected to the source, and the mosfet is symmetrical, meaning what is labeled drain in the data sheet is actually the source by definition of being attached to power? This would mean the gate is low? I just realized I could measure this, but I'll post anyway as it is an interesting question and I am out of the office until tomorrow...
I accidentally wired a p-mosfet with power at the drain, and default same voltage at the gate. If the power we're at the source I would expect the led load to be normally off when the gate is high, and on when the gate is pulled low. Right now the led is normally on. I thought this could be because the resulting Vgs is less than zero, but I am wondering why the drain-source is conducting. Since it is conducting, is the body diode not connected to the source, and the mosfet is symmetrical, meaning what is labeled drain in the data sheet is actually the source by definition of being attached to power? This would mean the gate is low? I just realized I could measure this, but I'll post anyway as it is an interesting question and I am out of the office until tomorrow...