LED tolerances in typical voltages

[boncker]

Does anyone know the tolerance in typical voltages and current of some leds? I'm using a led from Sunled (XLMR01DH) that in normal conditions it drives 20mA @ 1,85V. I put eight leds in series with 14.5Vdc and a current of 20mA. The maximum voltage I found in a led 1.83V and 1.78V in another one.

Is this difference normal in leds?

 

[kender]

Re: LED tolerances

I don't know the direct answert to your question about the batch variation of the forward voltage drop. But I know that the forward voltage drop depends on: temperature, current and light falling onto the LED.

 

[A.Anand Srinivasan]

Re: LED tolerances

this variation is quite normal... you cant expect all the LEDs to have the same parameters... i remember seeing in a video lecture that the ICs or semiconductor device of a particular batch have some amount of parameter mismatch due to little variation in their manufacturing conditions,,... but there will surely be variation among them too,,....

 

[Kral]

Re: LED tolerances

boncker,
This kind of variation is normal. That is why LEDs are usually driven from a current source.
Regards,
Kral