All correspondence concerning this article should be addressed to
Prof. John WyattThis 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 approximatioSupported by the National Science Foundation Contract No. 94-23221
