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Value of Vout in PMOS Inverter?

  1. Feb 6, 2013 #1
    Hey guys. I am simply trying to derive the equation for Vout in a PMOS inverter (attached). I know that in an NMOS inverter (which has the resistor in top of the transistor instead of the bottom) the equation for Vout is:

    Vdd - id*rd.

    But how does the resistor being in the bottom change this behavior? Is it now Vcc - ground? (which would equal Vcc).


    Attached Files:

  2. jcsd
  3. Feb 6, 2013 #2
    It could also be Vout = id * Rd.
  4. Feb 23, 2013 #3


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    Staff: Mentor

    If by Rd you mean that external resistor, then that looks right for output logic HIGH.
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