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.

Thanks.

 

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.

 

Do you know how to create a voltage controlled current source?

 

So what eqn or parameters you you set a VCCS to ? Can you put in a diode eqn ? What does the LED in there already, do then ?

 

So what eqn or parameters you you set a VCCS to ? Can you put in a diode eqn ? What does the LED in there already, do then ?

Apparently it is the B. source you need to use to get an expression.



An example

 

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.

Thanks.

here are some models to play with.
A test circuit is included.

 

here are some models to play with.
A test circuit is included.


View attachment 212170

will check it, thanks

 

here are some models to play with.
A test circuit is included.


View attachment 212170

This thing gives me 58 mA of current on load resistor, when i give 5V on VLIGHT and 5V on V1, I don't think its possible with tiny led reversed biased to work as photo diode.

 

This thing gives me 58 mA of current on load resistor, when i give 5V on VLIGHT and 5V on V1, I don't think its possible with tiny led reversed biased to work as photo diode.

VIN=1V per 1W optical power
You've just applied 5W of optical power to the diode.

 

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 https://www.cordellaudio.com/book/spice_models.shtml

 

here are some models to play with.
A test circuit is included.


View attachment 212170

How can I change the parameters from the default settings