The DC characteristics of the diode are determined by the parameters IS and N. An ohmic resistance, RS, is included which WinSpice defaults to 0.01 ohms if not specified to prevent convergence problems.

Charge storage effects are modelled by a transit time, TT, and a non-linear depletion layer capacitance which is determined by the parameters CJO, VJ, and M.

The temperature dependence of the saturation current is defined by the parameters EG, the energy and XTI, the saturation current temperature exponent. The nominal temperature at which these parameters were measured is TNOM, which defaults to the circuit-wide value specified on the .OPTIONS control line.

Reverse breakdown is modelled by an exponential increase in the reverse diode current and is determined by the parameters BV and IBV (both of which are positive numbers).

.MODEL <model name> D [model parameters]


Parameter Description Default Units Area
IS Saturation current 10-14 A *
RS Ohmic resistance 0.01 Ω *
N Emission coefficient 1  
TT Transit-time 0.0 s  
CJO Zero-bias junction capacitance 0.0 F *
VJ Junction potential 1 V  
M Grading coefficient 0.5    
EG Activation energy 1.11 eV  
XTI Saturation-current temp. exp 3.0     
KF Flicker noise coefficient 0    
AF Flicker noise exponent 1    
FC Coefficient for forward-bias depletion capacitance formula 0.5    
BV Reverse breakdown voltage V  
IBV Current at breakdown voltage 10-3  A  
TNOM Temperature at which the model parameters were measured. If this value is specified overrides the nominal TNOM value which is set in the options.   °C  
TABS Specifies the temperature at which the component operates. This value, if specified, takes precedence over the analysis temperature.    °C  
TREL Device temperature relative to current temperature. If this parameter is specified but not the parameter TABS then the current temperature of the component is equal to the current temperature plus TREL.    °C  


.MODEL DMOD D ( IS=1p CJO=0.2p )

See also