SPICE simulation of thermistors and thermistor circuits

A negative-coefficient thermistor model implementation is presented for simulation with SPICE. The thermistor model takes into account the ambient temperature, the nonlinear dependence of the thermistor resistance versus temperature, and the effects associated with the power dissipated in the thermistor. The application presented is an operational amplifier Wien-bridge oscillator with thermistor amplitude stabilization. The simulation results are closely related with the real oscillator output response.