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Impedance Vs time delay

  1. Nov 14, 2014 #1
    I recently attended a seminar, which said impedance increases with temperature, which results in timing delays in digital circuits. I don't understand how increase in impedance results in delay.
  2. jcsd
  3. Nov 14, 2014 #2


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    Staff: Mentor

    The thermal coefficient of resistance varies for different materials. Resistance decreases for some semiconductors with increasing temperature, right?

    So I assume they were talking about the metal traces in ICs and their thermal coefficient of resistance, which does increase with temperature. Since a big part of the delay in those IC traces is the RC delay, increasing the R (and not changing the C) will result in more delay.
  4. Nov 14, 2014 #3


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    Gold Member

    You need a more specific quote, a reference to a particular circuit. It's possible that increased impedance could change the phase in some parts of a circuit but without any specific information, that is, just taken as a bald statement with no context, it makes no sense as far as I can see. For one thing not all impedance increases with temperature.
    Last edited: Nov 14, 2014
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