I want to plot the thermal impedance vs pulse width tp at different duty-cylce for a mosfet in pspice. I've the RC thermal network with me.
I could plot for single shot but not able to plot at different duty-cycle.
If I understand the problem correctly, you want to plot impedance with pulse-width as x-axis.
If yes, you can make pulse width as parameter and run parameteric sweep.
Then go to menu - Trace -> Performance Analysis.
There you can easily plot any measurement with pulse width as x-axis.