Generalizations of the Klaassen-Prins equation for calculating the noise of semiconductor devices

The Klaassen-Prins equation is the standard equation for calculating the drain thermal noise of long-channel MOSFETs. We show that the Klaassen-Prins equation is not always valid, even for MOSFETs. We present generalizations to the Klaassen-Prins equation that include velocity saturation effects of short-channel MOSFETs and that comprise also induced gate noise.