Thermodynamic Validity of Noise Models for Nonlinear Resistive Devices

: The first result of this paper gives the shot-noise amplitude for a class of nonlinear resistances. The noise behavior for equilibrium and nonequilibrium bias conditions is uniquely specified by the voltage-current relation and thermodynamic constraints. Secondly, we show that the Gaussian model cannot be applied to any nonlinear device. While the Gaussian model can be a useful approximation, it cannot be physically correct. Introduction This paper investigates the thermodynamic validity of two widely-used classes of noise models for semiconductor devices, the Gaussian and the shot-noise models. Specifically, we examine a circuit consisting of a capacitor connected across the noisy device to see if the models predict that 1) the equilibrium probability distribution for the capacitor charge is MaxwellBoltzmann in form, and 2) the total entropy of the circuit increases monotonically in time as the circuit relaxes to an equilibrium charge distribution. Poisson Device Models The shot..