The junction diode model is a simple diode with an exponential characteristic. The diode formula essentially is:
f = Is*(exp(e/Vt) - 1)
However, if the exponent e/Vt reaches either an upper limit EMax or a lower limit Emin, the diode characterisic is linearly continued to avoid overflow or underflow, respectively.
The causality of the junction diode element is free.
Potential variables: e1: Bondgraphic effort variable of inflow f1: Bondgraphic flow variable of inflow, normalized positive for flows into the model e2: Bondgraphic effort variable of outflow f2: Bondgraphic flow variable of outflow, normalized positive for flows out of the model Parameters: Tnom: Reference temperature (default value = 300.15 K) Is: Transport saturation current (default value = 1e-16 Amp) EG: Energy gap for temperature effect on saturation current (default value = 1.11 Volt) N: Current emission coefficient (default value = 1) XTI: Saturation current temperature exponent (default value = 3) EMin: Minimum exponent (default value = -100) EMax: Maximum exponent (default value = 40)
Equations:
RTemp = e2/Tnom
ISval = IS*exp((RTemp - 1)*EG/Vt + XTI*ln(RTemp))
ExMin = exp(EMin)
ExMax = exp(EMax)
et = e1/(Vt*N)
f1 = ISval*(if et < EMin then ExMin*(et - EMin + 1) - 1 else
if et > EMax then ExMax*(et - EMax + 1) - 1 else exp(et) - 1)
f2 = 0