Diode 2
Improved diode model
Description
Equations
Variables
Connections
Parameters
Modelica Standard Library
The Diode 2 component extends the basic Diode as follows:
It models reverse breakdown.
The parameters are those typically published for real-world diodes.
A series resistance has been added.
The parallel resistance has been replaced by a conductance, which can be set to zero.
The model consists of a pure diode section, a resistance, Rs, in series with the pure diode, and a conductance, Sp, in parallel with the pure diode. The current, Id, through the pure diode is given in the following table.
Region
Condition
Current
Lower half of reverse biased region.
Vd<−Bv2
Id=−Ids⁢exp⁡−Vd+BvN⁢VT+1−2⁢exp⁡−Bv2⁢N⁢VT
Upper half of reversed biased region, and forward biased region before conduction.
−Bv2≤Vd<Vd⁡max
Id=Ids⁢exp⁡VdN⁢VT−1
Forward biased region after conduction.
Vd≥Vd⁡max
Id=IVd⁡max+Vd−Vd⁡max⁢GVd⁡max
where
Vd is the voltage across the pure diode,
VT=k⁢Tq is the thermal voltage (k is the Boltzmann constant, q is the elementary charge),
Vd⁡max=Vf+N⁢VT is the linear continuation threshold,
IVd⁡max=Ids⁢exp⁡Vd⁡maxN⁢VT−1 is the current at that threshold, and
GVd⁡max=Ids⁢exp⁡Vd⁡maxN⁢VTN⁢VT is the conductance at the threshold.
i=ip=−in=Vd⁢Sp+{−Ids⁢exp⁡−Vd+BvN⁢VT+1−2⁢exp⁡−12⁢BvN⁢VTVd<−Bv2Ids⁢exp⁡VdN⁢VT−1Vd<Vd⁡maxiVd⁡max+Vd−Vd⁡max⁢GVd⁡max
v=vp−vn=Rs⁢i+Vd
Td={TheatPortUse Heat PortTotherwise
VT=k⁢TheatPortq
LossPower=v⁢i
Name
Units
Modelica ID
v
V
Voltage drop between the two pins
vx
Voltage at pin x, x∈n,p
x.v
i
A
Current flowing from pin p to pin n
ix
Current into pin x, x∈n,p
x.i
LossPower
W
Loss power leaving component via HeatPort
TheatPort
K
Temperature of HeatPort
T_heatPort
p
Positive pin
n
Negative pin
Heat Port
Conditional heat port
heatPort
Default
Bv
100
Reverse breakdown voltage
Ids
1·10−13
Reverse saturation current
N
1
Emission coefficient
Rs
16
Ω
Series resistance
Gp
1·10−6
S
Parallel conductance for numerical stability
T
293.15
Fixed device temperature if Use Heat Port is false
Vf
0.7
Forward voltage
VT
Modelica.Constants.R⁢TModelica.Constants.F
Thermal voltage (kT/q), 0.026 at normal conditions (around 20 degC)
Vt
Use Heat Port
false
True (checked) means heat port is enabled
useHeatPort
The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.
See Also
Diodes
Electrical Library
Semiconductors
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