Diode 2 - MapleSim Help
For the best experience, we recommend viewing online help using Google Chrome or Microsoft Edge.

Diode 2

Improved diode model

Description

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 • The parallel resistance has been replaced by a conductance, which can be set to zero.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, ${R}_{s}$, in series with the pure diode, and a conductance, ${S}_{p}$, in parallel with the pure diode. The current, ${I}_{d}$, through the pure diode is given in the following table.

 Region Condition Current Lower half of reverse biased region. ${V}_{d}<-\frac{{B}_{v}}{2}$ ${I}_{d}=-{I}_{\mathrm{ds}}\left(\mathrm{exp}\left(-\frac{{V}_{d}+{B}_{v}}{N{V}_{T}}\right)+1-2\mathrm{exp}\left(-\frac{{B}_{v}}{2N{V}_{T}}\right)\right)$ Upper half of reversed biased region, and forward biased region before conduction. $-\frac{{B}_{v}}{2}\le {V}_{d}<{V}_{d\left(\mathrm{max}\right)}$ ${I}_{d}={I}_{\mathrm{ds}}\left(\mathrm{exp}\left(\frac{{V}_{d}}{N{V}_{T}}\right)-1\right)$ Forward biased region after conduction. ${V}_{d}\ge {V}_{d\left(\mathrm{max}\right)}$ ${I}_{d}={I}_{{V}_{d\left(\mathrm{max}\right)}}+\left({V}_{d}-{V}_{d\left(\mathrm{max}\right)}\right){G}_{{V}_{d\left(\mathrm{max}\right)}}$

where

 • ${V}_{d}$ is the voltage across the pure diode,
 • ${V}_{T}=k\frac{T}{q}$ is the thermal voltage (k is the Boltzmann constant, q is the elementary charge),
 • ${V}_{d\left(\mathrm{max}\right)}={V}_{f}+N{V}_{T}$ is the linear continuation threshold,
 • ${I}_{{V}_{d\left(\mathrm{max}\right)}}={I}_{\mathrm{ds}}\left(\mathrm{exp}\left(\frac{{V}_{d\left(\mathrm{max}\right)}}{N{V}_{T}}\right)-1\right)$ is the current at that threshold, and
 • ${G}_{{V}_{d\left(\mathrm{max}\right)}}=\frac{{I}_{\mathrm{ds}}\mathrm{exp}\left(\frac{{V}_{d\left(\mathrm{max}\right)}}{N{V}_{T}}\right)}{N{V}_{T}}$ is the conductance at the threshold.
 Equations $i={i}_{p}=-{i}_{n}={V}_{d}{S}_{p}+\left\{\begin{array}{cc}-{I}_{\mathrm{ds}}\left(\mathrm{exp}\left(-\frac{{V}_{d}+{B}_{v}}{N{V}_{T}}\right)+1-2\mathrm{exp}\left(\frac{-1}{2}\frac{{B}_{v}}{N{V}_{T}}\right)\right)& {V}_{d}<-\frac{{B}_{v}}{2}\\ \phantom{\rule[-0.0ex]{0.5ex}{0.0ex}}{I}_{\mathrm{ds}}\left(\mathrm{exp}\left(\frac{{V}_{d}}{N{V}_{T}}\right)-1\right)& {V}_{d}<{V}_{d\left(\mathrm{max}\right)}\\ {i}_{{V}_{d\left(\mathrm{max}\right)}}+\left({V}_{d}-{V}_{d\left(\mathrm{max}\right)}{G}_{{V}_{d\left(\mathrm{max}\right)}}\right)\end{array}$ $v={v}_{p}-{v}_{n}={R}_{s}i+{V}_{d}$ ${T}_{d}=\left\{\begin{array}{cc}{T}_{\mathrm{heatPort}}& \mathrm{Use Heat Port}\\ T& \mathrm{otherwise}\end{array}$ ${V}_{T}=k\frac{{T}_{\mathrm{heatPort}}}{q}$ $\mathrm{LossPower}=vi$

Variables

 Name Units Description Modelica ID $v$ $V$ Voltage drop between the two pins v ${v}_{x}$ $V$ Voltage at pin $x$, $x\in \left\{n,p\right\}$ x.v $i$ $A$ Current flowing from pin p to pin n i ${i}_{x}$ $A$ Current into pin $x$, $x\in \left\{n,p\right\}$ x.i $\mathrm{LossPower}$ $W$ Loss power leaving component via HeatPort LossPower ${T}_{\mathrm{heatPort}}$ $K$ Temperature of HeatPort T_heatPort

Connections

 Name Description Modelica ID $p$ Positive pin p $n$ Negative pin n $\mathrm{Heat Port}$ heatPort

Parameters

 Name Default Units Description Modelica ID ${B}_{v}$ $100$ $V$ Reverse breakdown voltage Bv ${I}_{\mathrm{ds}}$ $1·{10}^{-13}$ $A$ Reverse saturation current Ids $N$ $1$ $1$ Emission coefficient N ${R}_{s}$ $16$ $\mathrm{\Omega }$ Series resistance Rs ${G}_{p}$ $1·{10}^{-6}$ $S$ Parallel conductance for numerical stability Gp $T$ $293.15$ $K$ Fixed device temperature if Use Heat Port is false T ${V}_{f}$ $0.7$ $V$ Forward voltage Vf ${V}_{T}$ $\frac{\mathrm{Modelica.Constants.R}T}{\mathrm{Modelica.Constants.F}}$ $V$ Thermal voltage (kT/q), 0.026 at normal conditions (around 20 degC) Vt $\mathrm{Use Heat Port}$ $\mathrm{false}$ True (checked) means heat port is enabled useHeatPort

 Modelica Standard Library 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.