NGSpice (on linux): PMOS doesn't seem to work!

Discussion in 'General Electronics Chat' started by spacewrench, May 27, 2010.

  1. spacewrench

    Thread Starter Member

    Oct 5, 2009
    58
    1
    I'm trying to do some simple simulations on Linux (Ubuntu), and the easy_spice package seems to work pretty well, but I can't figure out how to get PMOS transistors working. I've tried them flipped D/S, with the base terminal connected to D or S, but they never turn on as I expect (when Vgs is negative). I'd appreciate it if anybody who understands this stuff can explain what I'm doing wrong in small words...

    My test circuit:

    [​IMG]
    The netlist:
    * Spice netlister for gnetlist
    R22 Out2 1 2.2k
    R21 4 in 10
    M3 1 in Out3 Out3 PCH L=1u W=200u
    M4 Out3 in 6 6 NCH L=1u W=200u
    R11 2 in 10
    R12 3 Out1 2.2k
    M2 Out2 4 5 5 NCH L=1u W=200u
    M1 Out1 2 1 1 PCH L=1u W=200u
    Vmeter3 6 0 0
    Vsig in 0 PULSE 0 5 1uS 120nS 200nS 7uS 20uS
    Vmeter2 5 0 0
    Vmeter1 3 0 0
    VDD 1 0 5
    .END
    The plot:
    [​IMG]
     
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