Silicon carbide junction field effect transistor
(SiC-JFETs) is a mature power switch newly applied in several industrial
applications. SiC-JFETs are often simulated by Spice model in order to
predict their electrical behaviour. Although such a model provides
sufficient accuracy for some applications, this paper shows that it presents
serious shortcomings in terms of the neglect of the body diode model, among
many others in circuit model topology. Simulation correction is then
mandatory and a new model should be proposed. Moreover, this paper gives an
enhanced model based on experimental dc and ac data. New devices are added
to the conventional circuit model giving accurate static and dynamic
behaviour, an effect not accounted in the Spice model. The improved model is
implemented into VHDL-AMS language and steady-state dynamic and transient
responses are simulated for many SiC-VJFETs samples. Very simple and
reliable optimization algorithm based on the optimization of a cost function
is proposed to extract the JFET model parameters. The obtained parameters
are verified by comparing errors between simulations results and
experimental data.