Attached circuit I want the Nmos to pull to the ground but it is not doing so. Voltage at vout is 8.559V not close to 0V. Can anyone explain why this is happening and how to pull the Nmos to ground?



Please delete another forum in Digital Design forum. Put in wrong place.

 

Where is node 002?

 

Where is node 002?

Its at vout in the post #1 image

 

The voltage is developing across D1 and R1 on a current path independent of the NMOS.

 

The voltage is developing across D1 and R1 on a current path independent of the NMOS.

But if Nmos is closed then inductor shunts to ground and then their should be no voltage. However NMOS is not closing it seems? How to close the Nmos?

 

But if Nmos is closed then inductor shunts to ground and then their should be no voltage.

You are testing at DC not AC. The inductor has almost 0 ohms of resistance. Massive amounts of current is flowing.
Change the Gate voltage from a battery to a square wave voltage source. On voltage=12V off voltage = 0V Frequency = 100khz.

 

Well, the transistor can only "close" but so much, then the voltage will develop across the highest resistance.

 

Plot the current through the MOSFET.

 

But if Nmos is closed then inductor shunts to ground and then their should be no voltage. However NMOS is not closing it seems? How to close the Nmos?

Replace the inductor with a 1 ohm resistor.

 

Add series resistance to the inductor.