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white LED model testing for forward voltage and current

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allennlowaton

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hello guys..
I am currently simulating a white LED model that I found on the internet.
Can somebody explain here each of the variables in the model? I want to find the forward voltage as well as the forward current for this model.

.model WLED D(Is=1e-36 N=1.923 Rs=32.09 Eg=3.6 Cjo=63.87p M=0.1513
+ Vj=2.02 Fc=0.5 Isr=1.304m Nr=1.4Meg Bv=12 Ivb=369.5u
+ Tt=432.8n Xti=5)

Thank you very much...
 

Right. But what is Isr ?

"Recombination current parameter" according to my Spice documentation (SIMetrix). It doesn't seem to be in the Hspice documentation so I guess it is a Pspice parameter (SIMetrix accepts Pspice & Hspice models).



It appears in equations with temperature effects as well.

Keith.
 
I also obtain this information from the .lis file.

**warning** unknown model parameter: isr


**warning** unknown model parameter: nr

These two are not known in Hspice.
 

Yes, they are Pspice parameters. Just remove them. I have run a simulation of V/I for the diode and cannot see any difference in the results. It may have an effect with modulation or recovery from reverse breakdown - I don't know because I don't know what they are really for. erikl may be able to help.

Keith.
 
Thank you keith.
The I/V for this model shows that after Vin =3v, the current behaviour is linear.
But, as I tried to look at some white LED specs, the current behaviour is exponential.
Can you suggest some variables to be varied so that I can obtain an IV graph closely related with the existing products.
 

**warning** unknown model parameter: isr
recombination current parameter - thanks Keith ! - not essential for forward current characteristic

**warning** unknown model parameter: nr
equivalent noise resistance
not necessary for forward current characteristic - just remove both of them.

---------- Post added at 11:35 ---------- Previous post was at 11:18 ----------

... so that I can obtain an IV graph closely related with the existing products.
Did you try the simple white LED model by electronrancher (above marshel's posting, where you possibly found this complicated WLED model ;-) ) ?

Or you might try a model of OSRAM's Golden Dragon Spice models lib.
 
thank you erikl.
do you have an information on what actual product does the OSRAM model represented?
I have found out that this model has 1.9volts when there's 20mA on it.

yeah. the model by electrorancher has 3.4-3.5 volts when there's 20mA.
 

thank you erikl.
do you have an information on what actual product does the OSRAM model represented?
I have found out that this model has 1.9volts when there's 20mA on it.
OSRAM's Golden Dragon are high-power LEDs thought for 300..400mA operation. See **broken link removed** Even at these currents they own much smaller forward voltage (only 2.0..2.2V).
 
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