A question about LTSpice, quick help please

[hidir11]

In LTSPICE, I've built a pseudo-NMOS inverter and I've got 2 tasks to do using it.

1) I've a initial guess for Wn value of NMOS. I start the simulation with this value however, I need to optimize it and get a more precise value.

Basically, when Vol < x for some x, I need to find the minimum Wn value that satisfies this inequality.

2)Initially, nothing is connected to the output of inverter. Then, I connect a capacitor after finding my Wn value. At this point I need to find LOW-to-HIGH delay of the inverter.

I think I need a DC sweep for the first one. But don't know how to extract my value.

I have no idea for the second one though.

Any help is much appreciated.

 

[crutschow]

For finding the time delay you would use the Transient response simulation. Click on the input and output nodes to plot their waveforms. Double-click on the node names at the top of the plot to generate two cursors to measure the delta time between the input and output signals.

 

[hidir11]

I just got this one. Still working on first one though.