SIMPLORER User Manual V6.0 - FER-a

Electrical Model
SIMPLORER 6.0 — Manual 141
The model uses an electrical equivalent circuit as shown in the figure below.
There are two simulation levels regarding the electrical behavior. The level is set at the parameter
TYPE_DYN:
TYPE_DYN=0
Only the static behavior is calculated. The charges at the capacitances are ignored, no
switching behavior.
TYPE_DYN=1
In addition to the static behavior, charging and discharging of the junction and diffusion capacitances
are calculated.
Electrical Behavior Level, Type DYN=0
The static transistor current is determined by the two BJT models for normal and inverse operation.
In the normal operation mode, where the internal base-emitter voltage and the collector-emitter
voltage are above 0 V, the current gain values for the BJT models are calculated
from:
BN = BN0 ⋅ ⎛1+ -------------------------
VCE ⎞ B
⎝ VEARLY⎠
I = BI0
In the inverse mode applies:
BN = BN0 BI= BI0 ⋅ ⎛1– -------------------------
VCE ⎞
⎝ VEARLY⎠
The static collector current is calculated from the base currents of the BJT models:
IC = BN ⋅ IBN – IBI( 1 + BI) The base currents of the BJT models are calculated from their base-emitter voltages:
VBE∗
⎛ ----------------------------- ⎞
M_BJT ⋅ VT I I ⎜
B∗ SAT e – 1⎟
k ⋅ ( TEMP_JNCT + 273K)
= ⋅
V
⎜ ⎟ T = ---------------------------------------------------------------q
⎝ ⎠
k = Boltzmann constant (1.381E-23) q =
Elementary charge (1.602E-19)