Detailed MOSFET (Datasheet)

Description

This MOSFET model is developed with two key objectives:

1. Accuracy and Computational Efficiency: The model accurately simulates both switching and static behaviors of MOSFETs and is optimized for fast simulation.
2. Robustness and Characterization: It is designed to be robust and can be easily characterized using a standard datasheet.

This MOSFET model incorporates:

• Three nonlinear capacitances $C_{GD}$, $C_{GS}$, and $C_{DS}$ characterized by Capacitance-$V_{DS}$ matrices, modeling $C_{ISS}$, $C_{OSS}$, and $C_{RSS}$ respectively.
• A PWL Diode representing the MOSFET body diode, characterized by a Voltage-Current data matrix.
• An internal piecewise linear MOSFET model using 3D Triangular meshing for output and transfer characteristics (details below).
• An internal gate resistance $R_G$.

### Capacitances

The capacitances are calculated as follows:

$$ C_{GS} = C_{ISS} - C_{RSS} $$

$$ C_{DS} = C_{OSS} - C_{RSS} $$

$$ C_{GD} = C_{RSS} $$

!!! important "Capacitance Consistency" It is recommended that all three capacitances share the same $V_{DS}$ values. If not, interpolation is used to calculate missing $V_{DS}$ values.

!!! important "Capacitance Options" Alternatively, a single capacitance value can be used to model a $V_{DS}$-independent capacitance.

### Body Diode

To accurately model the diode's off state, include at least one data point with a negative voltage in the characteristics matrix. In most cases, modeling avalanche breakdown is unnecessary.

### MOSFET Equations

The internal MOSFET model employs the following drain current equations:

Optimization techniques are employed to derive $V_{th}$, $\lambda$, and $K$ from the output and transfer characteristics data. The DIRECT (DIviding RECTangles) algorithm is used for this optimization, as described in:

• D. R. Jones, C. D. Pertunen, and B. E. Stuckmann, "Lipschitzian optimization without the Lipschitz constant," J. Optimization Theory and Applications, vol. 79, p. 157 (1993).

### Initialization

Initial $V_{DS}$ and $V_{GS}$ values can be set to avoid unphysical current values at $t=0$.

Library

Electrical > Semiconductors

Pins

Name	Description
Drain	Drain
Source	Source
Gate	Gate (Control Input)

Parameters

Name	Description
Rg	Gate Internal Resistance value, in Ohm
VgsIdMatrix	Drain-Source Current [A] vs Gate-Source Voltage [V]
VgsIdMatrix_Vds	Vds value corresponding to the Id vs Vds data
VdsIdMatrix	Drain-Source Current [A] vs Drain-Source Voltage [V]
VdsIdMatrix_Vgs	Vgs value corresponding to the Id vs Vds data
Ciss	Input Capacitance Ciss[F] vs Vds[V]
Coss	Output Capacitance Coss[F] vs Vds[V]
Crss	Reverse Transfer Capacitance Crss[F] vs Vds[V]
VgsInit	Initial Vgs Capacitor Voltage, in V
VdsInit	Initial Vds Capacitor Voltage, in V
Vsd_Is_BodyDiodeMatrix	Source Drain current vs Source-Drain Voltage (Body Diode)