﻿ 20-sim webhelp > Library > Iconic Diagrams > Electric > Components > Diode

# Diode

## Library

Iconic Diagrams\Electric\Components

Default

Exponential

## Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Electric).

## Description - Default

This is an ideal electrical diode. The model is a switch which is open when the voltage drop v < 0 and closed when the voltage drop v > 0. The heart of the model consist of a resistance that is changed by the input voltage from almost zero (on) to a very large value (off). By proper selection of the on and off resistances, they can be effectively zero and infinity in comparison to other circuit elements. The port p of the diode model has separate high and low terminals. The equations are:

p.i = p_high.i = p_low.i;

p.u = p_high.u - p_low.u;

voltage out causality:

R = if p.i > 0 then Ron else Roff end;

p.u = R * p.i;

current out causality:

R = if p.u > 0 then Ron else Roff end;

p.i = p.u / R;

## Interface - Default

 Ports Description p_high, p_low Both terminals of the Electric port p. Causality indifferent p Parameters Ron Roff Resistance when diode is turned on [Ohm] Resistance when diode is turned off [Ohm]

## Description - Exponential

This is an electrical diode described by an exponential expression. The port p of the diode model has separate high and low terminals. The equations are:

p.i = p_high.i = p_low.i

p.u = p_high.u - p_low.u

uT = (k * T) / e;

p.i = Is * (exp (p.u / uT) - 1);

with k the Boltzmann constant (k = 1.380658e-23 {J/K}

## Interface - Exponential

 Ports Description p_high, p_low Both terminals of the Electric port p. Causality indifferent p Parameters T Is operating temperature [K] reverse saturation current [A]