Interesting article about CREE Q5 and R2 bins

[DMC]

I came across this interesting article about CREE's Q5 and R2 bins
http://www.ledsmagazine.com/news/4/6/37

This table shows CREE Q5, R2, R3, and R5 bins with Lumens and Lms/watt
http://www.ledsmagazine.com/news/4/6/37/Creebins

The reported values for the new bins are at 350 mA, but you can approximate the values at 1000 mA using wintermute's Q4 graph:
http://www.cpfmarketplace.com/mp/showthread.php?p=2038282&mode=threaded#post2038282

 

[wintermute]

Based on Cree's Datasheets of the XR-E LEDs Current vs. Luminous Flux
@350mA - baseline
@750mA - 180% over baseline
@1000mA - 220% over baseline

Q4-bin @350mA: 100 - @750mA: 181 - @1000mA: 221
Q5-bin @350mA: 107 - @750mA: 193 - @1000mA: 235
R2-bin @350mA: 114 - @750mA: 205 - @1000mA: 250
R3-Bin @350mA: 122 - @750mA: 220 - @1000mA: 269
R4-bin @350mA: 130 - @750mA: 234 - @1000mA: 286
R4-max @350mA: 136 - @750mA: 245 - @1000mA: 299

Remember these are based on active cooling keeping the LED at 25 C. Not real world numbers in a light - but we're extremely close to the 300 lumens @ 1000mA mark. Biggest thing is, the R2 gets the magical number of 100lm/w and the R4 is rated at least at 115lm/w.

Excellent stuff - and I don't think we are even seeing their newest technology outlined here (i.e. the new blue die w/ ~50% efficiency).

 

[mossyoak]

the future is bright indeed.

 

[OhMyGosh]

What appeals to me:

P4 @ 1000mA =~ 180lm
Q5 @ 700mA =~ 180lm
R4 @ 500mA =~ 180lm

Interesting times indeed.

 

[jtr1962]

What appeals to me:

P4 @ 1000mA =~ 180lm
Q5 @ 700mA =~ 180lm
R4 @ 500mA =~ 180lm

Same here. What's interesting is if one does a rough calculation of the input power and waste heat:

P4 (Vf=3.9V, Pin=3.9W, efficiency=46.2 lm/W (~14%), waste heat=3.35W)
Q5 (Vf=3.7V, Pin=2.59W, efficiency=69.5 lm/W (~21%), waste heat=2.05W)
R4 (Vf=3.5V, Pin=1.75W, efficiency=102.9 lm/W (~31%), waste heat=1.21W)

As we go from the P4 to the R4 bins the input power needed for 180 lumens decreases by 55%. This translates into a 220% increase in runtime not even accounting for the fact that battery capacity increases somewhat as load decreases. This is already staggering, but the decrease in waste heat production of 64% is even more incredible. You only need to get rid of one-third of the heat for the same lumen production. Note that the waste heat for 180 lumens with an R4 emitter is about what one would have encountered with a Q-bin Luxeon emitter 3 years ago putting out only 35 lumens.

The best part of all this is even with the R4 bin we're not even halfway to the potential of LEDs!

 

[jtr1962]

One thing I forget to add to my previous post is that as we go up the efficiency curve the relative lumens when going from 350 mA to 1000 mA may increase because the higher efficiency will result in lower die temperatures. My test of a P4 earlier this year gave 85.7 lumens at 350 mA and 184.5 lumens at 1000 mA. This is a 215% increase despite the fact that the die most certainly wasn't held at 25°C (although the LED was well heat-sinked). I wouldn't be surprised if the R4 bins manage a 250% relative increase under real-world conditions, thus possibly putting out 325 lumens. I'm also sure any LEDs based on the new blue die should crack the 400 lumen barrier at 1000 mA with ease.

 

[curtis22]

One thing I forget to add to my previous post is that as we go up the efficiency curve the relative lumens when going from 350 mA to 1000 mA may increase because the higher efficiency will result in lower die temperatures.

Maybe this means that the new LEDs will be rated for more that 1.0 Amp.

 

[Gryloc]

Have you guys noticed the Cree datasheet and the curve for the Intensity vs. Current? A while ago (a few months), the line flattened out as the current approached 1A. I went ahead and hosted some snippets from the datasheet:



The first was from around May, I believe, while the second is the latest from this July. I was shocked when I first noticed this! I was excited to see this straighter line. This means more lumens at a higher power. Now, is this because the LEDs produce less heat, or because they are starting to create some sort of "anti-droop" technology like what Lumileds claimed to have? If it is because of less heat, then this current datasheet would be useless for the older, less efficient P-binned XR-Es. Hmmm...

I still need to compare the "Photometric Output vs Junction Temperature" to see if those changed. It is a good idea to hold on to older datasheets. It is fun looking back.

I, too, cannot wait untill Seoul P4s start using these more efficient dies. The phosphor they use seem to be more sensitive and efficient, so this change would be amazing. Plus, you got the well-focusable lambertian dome! Oooh, I forgot that tint shifts (for those who experienced them) will improve due to the less heat. Yipee!

I created an Excel worksheet comparing the intesity vs. current curve from the datasheet, from Newbie's findings, and another source (A chart made by another CPF member -was it you, jtr? I don't remember). From the "multipliers" (that curve -compared to the lumens at 350mA) were used to estimate the lumen output with the different, newer Cree XR-E bins. I will have to post it sometime if anyone wants it. The curves are pretty close to each other, but this new Cree datasheet set things apart again. I will have to add a new line on the chart using Cree's older specsheet. It would closer resemble Newbie's findings.

I was able to estimate (or predict) the lumen output at currents above 1A. Boy is that impressive! Sure, Cree and everyone else says that you should not "go over 1A". Newbie did the test up to 2A and things went fine for him. Actually, the numbers he got (lumens) at currents over 1A was used in my graphs. I want to do long term overdriving tests once I get (can afford) a good lab power supply, and a light meter (some day).

-Tony

 

[wintermute]

What appeals to me:

P4 @ 1000mA =~ 180lm
Q5 @ 700mA =~ 180lm
R4 @ 500mA =~ 180lm

Interesting times indeed.

That really appeals to me as well. Soon, we should be able to get to a point where we can have a 1xAA light with a respectable boost circuit (85-90% efficiency), which can put out 180lm for a decent amount of time. 500mA wouldn't need much for heat dissipation either.

I like the idea of super bright lights based on 1xAA NiMH batteries.

 

[IsaacHayes]

Gryloc, while the Seoul phosphor is more efficient, over time it seems to degrade as well, even when ran very cool and not abused. Newbie has some cool documented info on this. When it degrades it shifts to blue and that is even noted in the documentation from Seoul that it will shift.

Here is a graph of color shift over time newbie did. (went from a little over 6k to a little under 9k in 1400 hrs.) Here is the full page. He recorded 12% lumen loss in 1000 hrs. He also found that it seems to slow down and settle, that's good that it doesn't continue on loosing lumens. But it makes you think, what good is the more efficient phosphor if after 1000hrs it's settled in at 12% less in the end? Kind of moot hehe. This is with large heatsinking and slug temp under 30C, in a flashlight it could be worse or continue to loose lumens with the higher temps. How much is yet unknown. I do like the P4 for the lambertian beam as you pointed out. Just make sure you heatsink them well or keep currents low. For massive overdriving I like to use cree.

 

[Gryloc]

Yeah, I forgot about that. I read those posts a while back. Dang. At least initially, the Seoul P4's are hella-bright! Hopefully Seoul improves upon their product over time. Maybe Cree should attempt a similar package using better or higher quality methods. Either way, I wish that I could have the latest efficiency die put into a package where it is easy to use existing reflectors for the Lux (but does not have to be a direct drop in replacement to the Lux). A 180 degree radiation pattern is so nice at times. You can remove the dome and metal ring to achieve this well, but you have to be very careful when doing so to not shear off the bond wires. Then you have to keep everything protected. The Q-binned XR-Es are too expensive to risk to do that, though. Oh well...

Yes, like I said before, I would love to overdrive the new Q-binned (and of course R-binned) XR-Es with plenty of cooling. Brightness would be pure amazing! Finally, pair them with huge, deep, smooth reflectors.


-Tony

 

[2xTrinity]

Yes, like I said before, I would love to overdrive the new Q-binned (and of course R-binned) XR-Es with plenty of cooling. Brightness would be pure amazing! Finally, pair them with huge, deep, smooth reflectors.


-Tony

Maybe this means that the new LEDs will be rated for more that 1.0 Amp.

As LEDs get more and more efficient, I believe issues like thermal runaway might be more of a concern. As of now, waste heat, and power input are close to the same, as current LEDs are still fairly inefficient. However, consider a scenario where LEDs begin to approach ideal efficiency-- say 90% power efficiency, but overheating causes that to drop to 80% efficiency, even though the visible output isn't reduced by much, that represents a DOUBLING of the amount of waste heat being produced, which will in turn hurt efficiency even more... the definition of thermal runaway. IMO as LEDs get more efficient, current and overall output will be able to increase as a natural consequence, but at the same time, so will the need for thermal regulation.

 

[bfg9000]

He recorded 12% lumen loss in 1000 hrs.

Gee, this means after 1000 hours, the U-bin SSCs we've been enjoying all this time will be about as bright as a brand shiny new XR-E P4 bin.

Remember when new, the old U-Bin SSC P4 is as bright as a Q3-bin XR-E, and was available half a year earlier. I'm sure SSC is working to improve their phosphors just like CREE is, and hopefully the V-bin SSCs (118.5-154L so similar to CREE R4 bin) will be brighter and more durable.

 

[TorchBoy]

Gee, this means after 1000 hours, the U-bin SSCs we've been enjoying all this time will be about as bright as a brand shiny new XR-E P4 bin.

... but about as blue as a Smurf.

:nana:


:scowl:
:shakehead

 

[ensile]

That really appeals to me as well. Soon, we should be able to get to a point where we can have a 1xAA light with a respectable boost circuit (85-90% efficiency), which can put out 180lm for a decent amount of time. 500mA wouldn't need much for heat dissipation either.

I like the idea of super bright lights based on 1xAA NiMH batteries.

mother earth thanks CREE

 

[mountainpenguin]

hmm I have some questions.
I want to upgrade my apex pro. what is the brightest emmitter that will drop as replacement that i can buy in the next 4 weeks ?
and where can i get it from ?
I gather souls are a drop in so are there going to be new souls with the higher power emmitter ?

 

[Daekar]

hmm I have some questions.
I want to upgrade my apex pro. what is the brightest emmitter that will drop as replacement that i can buy in the next 4 weeks ?
and where can i get it from ?
I gather souls are a drop in so are there going to be new souls with the higher power emmitter ?

We haven't heard a peep out of SSC about new emitters as far as I know. I know people have done that mod with Crees as well as Seoul emitters - but I'm not sure what the beam looked like. I haven't seen any lamentation threads in the headlamp forum so I would assume OK. I'd pick up a Q4-bin Cree and go with it if you're really concerned about max output. I got a U-bin SSC and was very happy with it.

BACK ON TOPIC - I'm replacing the emitter in my MRV with a Q5, do any of you smart people with spreadsheets care to tell me what kind of output 1190mA on a Q5 would translate to?

 

[SemiMan]

RE: Change in the slope of the curve. The change looks like it represents about a 10% change in efficiency at 1A (maybe a touch less). This is likely from either small process improvements or from just as likely that they have qualified enough parts to have real world data to improve the data sheet values. It is more in line with the parts that I have been receiving all along.

It is nice that we are all getting excited about R4 bins, but we do not even have R2 bins yet! ... actually we have not even seen Q5 bins yet...at least in the real world.