This is because a device model is essentially an ideal model, whereas in order to represent the actual MOSFET characteristics, what is often actually used is a subcircuit model, obtained by adding parasitic components, temperature characteristics, and the like to a MOSFET device model that serves as the base. The reader will be wondering why we are considering a "MOSFET subcircuit model" when a device model was previously described. In the previous example, the device model for a MOSFET labeled "M1" appeared. The following is a description of the circuit and circuit connections of a subcircuit model for a ROHM Nch MOSFET. In the previous explanations, simple models were used to facilitate understanding here an actual Subcircuit model is used in explanations. In this model, the connection of the MOSFET M1 and the diode D1 is described. In the "model internal circuit connections", an instance name is followed by connection terminals and the model name. In the above example of a subcircuit model that combines an Nch MOSFET and a diode, the circuit connections, a device model of the MOSFET, and a device model of the diode are described. Subcircuit models are models of circuits, and such models include circuit connection information, device models, and other information. The basic configurations of device models and subcircuit models were explained in SPICE Model Types, but subcircuit models are somewhat complicated, and so are here briefly reviewed. In this article and the next, SPICE subcircuit models are explained, using MOSFETs as examples. In the previous article and in the article before that, examples of SPICE device models were explained.