# LED spice model in Eagle

#### rpschultz

Joined Nov 23, 2022
416
I've been modeling an LED (in Eagle) for a high school class I'm teaching. I found this "file" and imported it into the general diode model. It works, but doesn't exactly match values that I measure on a breadboard.

*Red LED
.MODEL DMOD D (IS=93.2P RS=42M N=3.73 BV=4 IBV=10U
+ CJO=2.97P VJ=.75 M=.333 TT=4.32U)
.MODEL DMOD D

The model puts out a Vf=1.8v for 20mA, and Vf=1.7v for 7mA.

I'm probably splitting hairs, but I'm just trying to understand what all those values in the model mean.

#### rpschultz

Joined Nov 23, 2022
416
So here's the simulation results for 3 different LED's, although the BLUE and WHITE give the same values.
RED has 20 mA
White and BLue have 10 mA.
Total current adds up to 40 mA as shown.

#### MrChips

Joined Oct 2, 2009
30,792
What's the problem?
Did you use the different models for RED, BLUE, and WHITE, as required?

#### dl324

Joined Mar 30, 2015
16,900
It works, but doesn't exactly match values that I measure on a breadboard.
It would be rare for a simulation to agree exactly, or even closely, with an actual breadboard.

#### rpschultz

Joined Nov 23, 2022
416
Yeah ok, it seems close. I'll have to dig into that link that @Papabravo has.

#### rpschultz

Joined Nov 23, 2022
416
Here are the values I found, for reference:

*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)