The MOSFET equivalent circuit model described incorporates short channel and temperature effects. It includes expressions for the device current in the subthreshold, triode and saturation regions and uses a field dependent mobility and a drain voltage dependent threshold voltage. The drain current-voltage characteristic and its first derivative are continuous in all regions. Relationships for the gate-source and gate-drain capacitances are derived as a function of the device potentials using a field dependent mobility. Using the closed form expressions of this model, simulations were performed for micron long devices having uniform and ion-implanted channel profiles and compared with data at room, above room and liquid nitrogen temperature.