PSPICE simulation of CMOS astable multivibrator

Discussion in 'Homework Help' started by stn0091, Mar 9, 2013.

  1. stn0091

    Thread Starter New Member

    Jan 11, 2013
    3
    0
    [​IMG]

    I want to simulate the above in OrCAD PSPICE. Here's my netlist:

    Code ( (Unknown Language)):
    1. * 8.20
    2.  
    3.  Vdd 1 0 5V
    4.  
    5.  MP1 3 2 1 1 PMOD
    6.  MN1 3 2 0 0 NMOD
    7.  
    8.  MP2 4 3 1 1 PMOD
    9.  MN2 4 3 0 0 NMOD
    10.  
    11.  R1 3 2 1000
    12.  C1 2 4 1uF
    13.  
    14.  .MODEL NMOD NMOS (VTO=2)
    15.  .MODEL PMOD PMOS (VTO=-2.0)
    16.  
    17.  .ic v(2)=5
    18.  
    19.  .tran 0.5us 10ms 0 1u uic
    20.  
    21.  .PROBE
    22.  .END
    Resistor and capacitor values were chosen for some arbitrary time constant. I just wanted to see the waveforms at Va, Vo and Vi.

    V(2) corresponds to the gates of the first CMOS and I set that to 5V to "start" the circuit. However, I'm not seeing any oscillations when I simulate the circuit.

    Where did I go wrong?
     
Loading...