Temperature Dependence Cgs

Discussion in 'General Electronics Chat' started by Bakez, Sep 25, 2013.

  1. Bakez

    Thread Starter Active Member

    Aug 21, 2012
    I have read in several texts the gate-source capacitance expressed in terms of Cox, W, and L.

    However I am wondering what its temperature dependence could be? I assume that W and L do not change with temperature, so it must be Cox is the temperature dependent parameter, which I find written as:


    So I assume that thickness does not change with temperature and it must be εox as the temperature dependent parameter. BUT then I read that with increasing temperature this dielectric property supposedly DECREASES with temperature, so Cgs sould also decrease? But I am sure it is the opposite

    I thought these capacitances were supposed to have an exponential relationship with temperature (a professor once told me this)

    I have also read in many application notes from large manufacturers that this capacitance is even indepedent of temperature!!!!

    So what is the deal? Does anyone know?