Accurate analog modeling of short channel FETs based o table lookup

A table-lookup model for MOSFETs has been implemented in SPICE 3, to overcome the inadequacies of analytical models that are unable to represent short-channel effects. The model comprises a 2-D main table, a coarse 3-D subtable to incorporate substrate effects, and a table to interpolate between channel lengths. There are 370 data points stored altogether. The tables are constructed from the measurement of incremental parameters, and thus reproduce transconductance and output conductance accurately, making the model superior for analog circuit design. The approach demonstrates improvement of 2-3 in total simulation time of a ring oscillator over the BSIM model in SPICE. The model affords a global accuracy of 4% in the I/sub d/-I/sub DS/ characteristics of 1- mu m enhancement and depletion MOSFETS.<>