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Trying to learn about netlists.

  1. May 1, 2006 #1
    I am trying to learn about transistor netlists and creating netlists for logic functions in SPICE.

    For a MOS Inverter, I know:

    Code (Text):

    .option post
    VG 2 0 DC PULSE 0 3 10NS 5NS 5NS 30NS 60NS
    VDD 3 0 DC  3V
    M1 1 2 3 3 pmos L=0.25U W=0.5U
    M2 1 2 0 0 nmos L=0.25U W=.25U
    .TRAN 10ps 150ns
    One of the big problems I'm having, I seemed to have not picked it up in class, is what this means:

    Code (Text):

    M1 1 2 3 3 pmos L=0.25U W=0.5U
    Now, I know those are some sort of parameters, maybe the sizing (I'm referring to the "1 2 3 3")?

    I assume M1 is the name of the single device we're creating. And I know what L and W are. But the 1 2 3 3 I'm pretty clueless about.


    Code (Text):

    VG 2 0 DC PULSE 0 3 10NS 5NS 5NS 30NS 60NS
    Now, obviously Vg values are being determined here. Does the first 2 mean Vg = 2V? What's the zero after mean?

    Code (Text):

    VDD 3 0 DC  3V
    I think here Vdd is just being defined as a 3V DC source. Since 3V is at the end, I assume the "3 0" does not mean 3V. What is the significance of the 3 there then?

    Googling produces a lot of random results, so if someone could just fill me in on what the number and what each position corrosponds to, I may be able to live a little longer!

    I get the idea that this stuff can be REALLY easy if you have a good reference source. Unfortunately, I don't. If you have a good site that just bluntly states what each position means, I would be VERY greatful!

    Thank you.
  2. jcsd
  3. May 1, 2006 #2
    M1 1 2 3 3
    means connect a mosfet with the drain at 1, gate at 2, source at 3 and substrate at 3.
  4. May 2, 2006 #3
    Thanks, corneo.

    I spent the day reading and asking people and I finally figured out what everything means. I can even design more complicated netlists. It is actually really simple once you get the basic idea down.
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