New MOSFET model suitable for analogue IC analysis

Abstract

A static MOSFET model suitable for analogue integrated circuit analysis has been evolved. It was considered that an active device model for analogue IC analysis should represent the device nonlinear conductance-voltage dependence adequately as well as current-voltage relation. The most important characteristics, I D-V DS and gds-VDS have been properly modelled. Precedence has been given to the modelling of channel-length modulation, which is the most dominant effect causing non-linearities of the I D-V DS and gds-V DS characteristics in the saturation region. With the aid of the developed model, I D-V DS and gds-VDS curves for an NMOS and a PMOS transistor have been estimated and are seen to fit adequately with the curves obtained from measurements. Distortion analysis using the new model has been carried out for a CMOS active-loaded amplifier to check the adequacy of the new model for analogue IC analysis. The results obtained are similar to the experimental results.