Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Pspice: derivative function in probe

  1. Feb 12, 2007 #1
    Hi Guys,
    I am stuck at a point and needs help.
    The thing is I am doing MOSFET inverters using Pspice.
    I am getting its VTC (voltage characteristic Curve) But I don't know how to get derivative of this curve in order to obtain some parameters required for Noise margin.
    Here is the file:

    .model NMOD NMOS (LEVEL=1, VTO=0.6 GAMMA=0 LAMBDA=0 KP=60U)
    .model PMOD PMOS (LEVEL=1, VTO=-0.8 GAMMA=0 LAMBDA=0 KP=20U)

    * CIRCUIT *

    VDD 3 0 DC 3
    VGS 1 0 DC 3
    M1 2 1 0 0 NMOD L=0.8U W=2U
    M2 2 1 3 3 PMOD L=0.8U W=10U
    .DC LIN VGS 0 3 0.1
    .PLOT DC V(2)

    I have 9.1 Student ,Demo version. I referred to user manual.... and it says I used use probe function 'd()' to get derivative but thats not working. It says invalid expressions.
    I am taking 'd()' at 'V(2)'.
    I would really appreciate if some one can help me out.
  2. jcsd
  3. Feb 13, 2007 #2
    I got it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook