Cree XP-L V6 2C led, tested against XM-L2 T6 3C, edit23/7: I repeated the test and measured a dedomed XP-L

Incredible job djozz! Your crash-test threads are always so informative. :smiley:

XP-L and XM-L2 both have the exact same die size (2mm x 2mm) right?

Whoa, this has to be the most accurate, disciplined emitter testing ever done by a "hobbist". I bet if the engineers a Cree see this, they will be saying, "why didn't we think of that on a couple points.

I am not near anything like your level, but I agree about not needing to adjust to Match's (another great maverick) numbers. The T6 designation was used for everything at the time. Some vendors now keep good track of the chain of custody, which is such a great improvement.

A far as this statement:

The more measurements I do, the less certain I am if what I am measuring is true (Confucius? ). So I hope they make sense and are useful, . . .

I can only imagine that the more precise you get, the more you are aware of more little potential error inducing issues. All I can say, is that no one that I'm aware of, has ever implemented such disciplined, diligent emitter output testing.

Correct (most likely) or not, it is the best we have here at BLF and probably any other forum by far. Thank you.

Given the smaller footprint, I say your results are impressive on the side of the XP-L.

Thanks for the testing, it is a great resource!

Thanks for the tests, this is great work

I am very disappointing with the XP-L, i expected a much stronger showing especially below 1.5A. If you used an XM-L2 U2 i can imagine them being neck and neck, in fact it may start out at a higher lumens then the XP-L which makes no sense because the XP-L is supposed to have 200 lumens at 1W instead of approximately 140 lumens.

great test

Nothing in the preliminary or published data indicated the XP-L would be anything other than a XM-L2 die stuck onto a smaller substrate. Unrealistic expectations based on false assumptions do tend to result in disappointment... :)

200 lumens per watt, compared to a XM-L2 U2 under the same conditions does something like 194 lumens per watt. Unremarkable.

source?

Cree's very own 'Product Characterization Tool' thingie.

Awesome…shows the XP-L is slightly outperforming the XM-L2…wow!

So much light in a teeny little footprint…how sweet it that!

Those suppliers on the XP-E/G type sinkpads better gear up :stuck_out_tongue:

of it's lower vf - meaning that a Liion for power the XM-L2 will produce full brightness for longer as the voltage drops, especially at high amps.

I think they’re rather slightly less efficient at the current levels we’re interested in. (3-6A)

The XP-L does have a higher lumen output but at a higher Vf. That is a big obstacle when trying to direct drive these LED’s.

But the small die size is a clear advantage, I can’t wait for super throwers using this LED. (TN31 or TK61 + XP-L at 5-6A)

Thanks for the tests djozz!

Do they? As I read some unofficial information both XP-L and XM-L2 have the same die size (2mm x 2mm). Now who can help to confirm this? The data sheet found in CREE website doesn’t specify this.

Die size is the same as XM-L2. So it wont throw better than XM-L2.

This will be future reference data. Like Tom E said, we need to know if you tested V5 or V6. My first impression when looking at these numbers are that Im not impressed with the XP-L. I expected it to be better. If you tested V6, then Im certainly not impressed based on the graph.

There are pics in the other XP-L thread of a dedomed XP-L and a dedomed XM-L2 and they are clearly both using the same die. It is a XM-L2 die stuck onto a 3.5x3.5 XP-sized substrate.

Whoops, sorry about that.

So no significant improvements over XM-L2 technology. :~

oops, that was a bit of sloppyness on my side, sorry about that, it is very important to mention the right bin and I made a mistake: I looked up the order confirmation from illumn.com and it was indeed a V6 bin that I ordered. So that leaves you all even less impressed . I corrected the OP!

Thanks to you all for the appreciation of the tests. I have one of these emitters leftover, it was next to the tested one in the same piece of reel. Out of curiousity, one of these days I will do an exact as possible same test on that one (but up to 8 amps, I don't want to loose this one) to see how consistant the results will be. Of course if the results do not exactly match I will never know if it is a difference in the emitter or an inconsistancy in the testing, but undoubtedly it will give some insight in something .

I wouldn’t call it an improvement so much as a variation and we like variety. Now you can more easily use an XP-L die on a 10mm sink pad with more room for wires and optic. The drop off at high current is unsurprising given the smaller center pad. What is surprising is it’s ability to run even with the larger footprint XM-L2 as long as it does. That might be due to the size of the heat sink though. The next issue will be getting small optics that fit the larger dome. Even with XP or Nichias a 10-15mm optic doesn’t focus too well.

This may be pretty much what I can do as a hobbyist, but there are some very easy major improvements if I just put more money into it (that I will not do for the time being):

1)have a light source officially measured so you do not have to rely on averaging multiple wacky sources,

2)put in a better luxmeter, not so much because those tend to be calibrated (which is of no use anyway when applied in a sphere), but because the better optical filtering makes the wavelength response follow the standardised human eye wavelength response better,

3)put in a wavelength analysing device. Texaspyro put some rgb sensors in his sphere and can measure colour temperatures and other interesting things going on with colour balance, pretty cool, but what you really want is a spectrofotometer with a handy sensor that you can stick into the sphere and that can produce true wavelength spectrums, so you can do colour analysing from that .

4) (and that is something I could do sometime) add a temperature sensor somewhere close to the led (relic38 did that during his copper board comparisons) and see what is happening there despite of the maximum cooling that I tried to achieve.