How to Simulate LED Photo diode in LT spice

Thread Starter


Joined Jun 9, 2020
Hello Members,

How to simulate 5 mm clear LED, color RED as photo diode in LT spice
Any simulation which I am able to download would be appreciated.



Joined Sep 17, 2013
You could simulate it as a voltage-controlled current or voltage source, depending on which mode the diode is to be used in. The voltage control would represent illumination.


Joined May 3, 2016
LTspice has several LEDs in its database of components. Select the LED symbol and place it into your schematic. Right-click over the symbol and select "Pick New Diode". You can also add models into the LTspice database (best to add a new directory for your models, just to keep LTspice clean), and select which of them you want to use. Here are three models I came across sometime in the past. They may help you to get started on modeling LEDs.

*Typ RED GaAs LED: Vf=1.7V Vr=4V If=40mA trr=3uS
.MODEL LED1 D (IS=93.2P RS=42M N=3.73 BV=4 IBV=10U
+ CJO=2.97P VJ=.75 M=.333 TT=4.32U)
*Typ RED,GREEN,YELLOW,AMBER GaAs LED: Vf=2.1V Vr=4V If=40mA trr=3uS
.MODEL LED2 D (IS=93.1P RS=42M N=4.61 BV=4 IBV=10U
+ CJO=2.97P VJ=.75 M=.333 TT=4.32U)
*Typ BLUE SiC LED: Vf=3.4V Vr=5V If=40mA trr=3uS
.MODEL LED3 D (IS=93.1P RS=42M N=7.47 BV=5 IBV=30U
+ CJO=2.97P VJ=.75 M=.333 TT=4.32U)

Cordell has some LED models also at