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Homework Help: Finding the forward current of diode

  1. Feb 17, 2017 #1
    1. The problem statement, all variables and given/known data
    A Si diode is operated at the room temperature (27 °C). For a forward current of 1 mA, the voltage VD is found to be 0.9 V. If the VD is 1 V, the forward current = _____ mA. Given that nVT = 26 mV

    The answer is 46.81

    2. Relevant equations
    Shockley diode equation?

    3. The attempt at a solution
    I tried to use the shockley diode equation, Id=Is exp(Vd/nVt)
    I subbed in values 0.9V and 1mA into eqn to get Is and then using newfound Is to sub into shockley diode eqn again with Vd 1V now. However, I didn't get the answer 46.81mA.

    Is there an assumption that I have made wrong? Any help in figuring my mistake out is greatly appreciated. Thank you so much!!
  2. jcsd
  3. Feb 17, 2017 #2


    User Avatar

    Staff: Mentor

    Please show your working so we can check it.
  4. Feb 17, 2017 #3
    Oh my gosh, as soon as I was typing out my steps and I finally got the answer. Must have keyed in wrong values somewhere in the calculator previously.
    So sorry for the trouble but thank you!!
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