MOS Model 31 is a physics based transistor model to be used in circuit simulation and IC-design of analogue high-voltage applications. The model describes the electrical behaviour of a junction-isolated accumulation/depletion-type MOSFET. The model is used as the drain extension of high-voltage MOS devices, like the Lateral Double-diffused MOS (LDMOS), the Vertical Double-diffused MOS (VDMOS), and the Extended MOS transistors.
The models are included in a dynamically loaded library called SiMKit. SiMKit is related to the following circuit simulators used within NXP®: