SPICE Subcircuit Models: MOSFET Example―Part 2

This is a continuation of Part 1 on SPICE subcircuit models of MOSFETs.

Relations between Device Model Parameters in a Subcircuit Model

The figure is a diagram of the MOSFET subcircuit model used in Part 1. The figure indicates how the MOSFET base model and the parameter settings for the diodes and resistances actually affect the characteristics.

Shown below are the various parameters and characteristic graphs obtained in simulations. Red text indicates parameters and the effect they have. Here it should be sufficient to try to grasp the various relationships.

Key Points:

・There are two types of SPICE models: “device models” and “subcircuit models”.

・Subcircuit models consist of connection information and device models.

・Subcircuit models may be constructed by imparting realistic characteristics to device models that represent ideal characteristics, and may constitute circuits with specific functions or the like.