Hi All,
I have been going thru several LED datasheets as I am trying to select a suitable part for my design. I quickly realized realiability/durability data is non standard, which I in fact verified after googling around a bit. At this point I stumble upon this reliability info for part CLU028-1201C4-303H5K2 on Digikey. I get the following data:
I am not sure what this data means as far as lumen maintenance goes.
My way of interpreting this is the following:
1. Continuous operation test, Tj will be way cooler in my application. So I can conclude that it will take more than 1000hs to get to "L85".
2. Same as 1) for storage temp.
3. Not sure what to conclude from this one.
4. Thermal cycling test seems like the only test I can use. It is running at an average 30C which is realistic, but incorporates some unrealistic cycling (As far as my application goes) and only adds up to 100 cycles x 1hr/cycle = 100hs!
So taking worst and best case scenarios I could expect my LEDs lumen maintenance to be somwhere between 100-1000hs (L85)?
That can't be right!
Where am I getting this wrong?
The only idea I have left is extrapolating the "Continuous Operation" or "Moisture Proof" info to some other temperature using the Arrhenius equation (same one used for AE caps life estimation)
Any ideas?
NOTE: My application is simple house illumination.