Extracting Transistor Charges from Device Simulations by Gradient Fitting

The results of small-signal or transient analyses from a conventional device simulator (or measured data) can be combined with gradient- fitting techniques to produce smooth spline-based MOSFET charge models for circuit simulation. The techniques presented for fitting splines to gradient data are also applicable to "shape from shading" and other problems. 

Results based on simulations of some small devices are presented. The comparative efficiencies of the small-signal and transient approach are discussed as well as the relation between the so-called small-and large-signal charges. The role of spline-based table models vis- a-vis compact analytical models is considered.