Author Topic: LTspice model for COB LED  (Read 1195 times)

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Offline ocsetTopic starter

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LTspice model for COB LED
« on: July 04, 2019, 05:17:20 am »
Hi,
Do you know how I can get a LTspice model for the LC019D and LC033D LEDs from Samsung?
Ie something that gives the same I,V curve when a DC sweep is done?
(pages 26,27 of datasheet)
https://cdn.samsung.com/led/file/resource/2018/09/Data_Sheet_COB_D_Series_Gen.3_Rev.2.3.pdf

I did the attached but its not accurate
 

Offline Ian.M

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Re: LTspice model for COB LED
« Reply #1 on: July 04, 2019, 09:59:01 am »
The curves in the datasheet don't have enough resolution so it will be difficult to fit a Berkeley SPICE diode model to them.   Best option is always a manufacturer supplied model -  *IF* LTspice can run it!

If they don't offer a model,  you can take one of the LEDs, run it at a very low current so you can count the number of  dies, then make a best guess how many parallel strings, and how many dies per string to get instance parameter N for the simulated diode, then put it on a curve tracer (preferably one that can do low duty cycle pulsed measurements to avoid self-heating effects, divide the voltages measurements by N and apply the fitting procedure documented at the link below, and you can get a pretty decent model out of it.

https://hackaday.io/project/12874-automated-ledlaser-diode-analysis-and-modeling/log/48368-estimating-spice-diode-models

For a detailed explanation of the Berkeley SPICE diode model, and its parameters see:
http://www3.imperial.ac.uk/pls/portallive/docs/1/7292572.PDF

« Last Edit: July 04, 2019, 11:02:47 am by Ian.M »
 
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