Nonlinear Device Noise Models: Thermodynamic Requirements

This paper proposes three tests to determine whether a given nonlinear device noise model is in agreement with accepted thermodynamic principles. These tests are applied to several models. One conclusion is that every Gaussian noise model for any nonlinear device predicts thermodynamically impossible circuit behavior: these models should be abandoned. But the nonlinear shot-noise model predicts thermodynamically acceptable behavior under a constraint derived here. Further, this constraint specifies the current noise amplitude at each operating point from knowledge of the device v − i curve alone. For the Gaussian and shot-noise models, this paper shows how the thermodynamic requirements can be reduced to concise mathematical tests involving no approximations. ∗All correspondence concerning this article should be addressed to Prof. John Wyatt Room 36-864 Massachusetts Institute of Technology 77 Massachusetts Avenue Cambridge, MA 02139 e-mail: [email protected] phone: (617) 253-6718 FAX: (617) 258-5846