# Any News On The XM-L2?



## CyberCT (Sep 6, 2012)

I have previously read that CREE was working on the XM-L2 like they have with the XP-G2. While there is plenty of news and even lights now coming out with the XP-G2 LED, I haven't seen anything on the XM-L2. Anyone have any news or updates?


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## A10K (Sep 6, 2012)

I've never read any news on the XM-L2. There was a lot of speculation tacked onto XP-G2 discussion, some of which probably got passed around as fact, and a few supposed CREE insiders hinting at things from behind their NDAs, but I've yet to see anything concrete on the matter.

Also, no XP-E2 or any such stuff... unless any supposed CREE insiders are willing to chip in...

(don't, really, I don't want to see you banned)


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## easilyled (Sep 20, 2012)

BTTT.


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## MichaelW (Sep 24, 2012)

I hope they come out with a xm-l 'junior', 3mm^2 instead of 4.


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## HumanLumen (Dec 6, 2012)

An E-mail from cutter TODAY states that they are giving away free samples of the XM-L2 (subject to other purchases) so they must be commercially close for sale.

HL


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## hellokitty[hk] (Dec 6, 2012)

Yay I was right about to place an order for an XM-L T5 5C to satisfy my neutral desires!
I have not gotten that email though and I did get email alerts from Cutter before...
Can you tell me if it's the same footprint? I hope it is as I've been making a heatsink...


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## WeLight (Dec 6, 2012)

A10K said:


> I've never read any news on the XM-L2. There was a lot of speculation tacked onto XP-G2 discussion, some of which probably got passed around as fact, and a few supposed CREE insiders hinting at things from behind their NDAs, but I've yet to see anything concrete on the matter.
> 
> Also, no XP-E2 or any such stuff... unless any supposed CREE insiders are willing to chip in...
> 
> (don't, really, I don't want to see you banned)




what do you mean no XPE-2 Stuff? these are available


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## uk_caver (Dec 6, 2012)

WeLight said:


> what do you mean no XPE-2 Stuff? these are available


The thread's been a bit of a slow burner - that comment was from September.


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## RoGuE_StreaK (Dec 6, 2012)

To me, the spec graphs of the XP-G2 seem very close to the XM-L, with the obvious exception of die size and max current; ie., Vf vs current, lumens at _x_ amount of current, etc. Essentially MichaelW's "XM-L junior"?
So, if that's where the new gen of XP-G is, what can we expect from a new gen of XM-L? :thinking:


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## uk_caver (Dec 6, 2012)

RoGuE_StreaK said:


> To me, the spec graphs of the XP-G2 seem very close to the XM-L, with the obvious exception of die size and max current; ie., Vf vs current, lumens at _x_ amount of current, etc. Essentially MichaelW's "XM-L junior"?


Overlaying the datasheet curves for '% lumimous flux'-vs-current for the XP-G at 25°C and the XP-G2 at 85°C, after correcting for the very slightly different vertical scale, they appear to be not merely very similar, but effectively indistinguishable, to the point where I wonder if they actually drew a new curve for the XP-G2 datasheet.

There's even the same kink at 1000mA.

Still, the underlying physics is presumably going to be very similar, and I'm assuming the curve is still effectively correct, so 'high temperature XP-G' might be an equally meaningful term.


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## uk_caver (Dec 6, 2012)

duplicate post deleted


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## LowLumen (Dec 7, 2012)

To see the difference between XP-G vs. XP-G2, look at the Vf curve.


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## uk_caver (Dec 7, 2012)

There is a significant difference in terms of change of Vf with current - XP-G2 only changes ~200mV from 350 to 1000 compared to the XP-G's ~350mV.

That said, the graphs do look a little more different than the devices might be in practice in terms of absolute Vf.

The XP-G graph shows a 350mA Vf of 3.0V, which seems to be rather above the typical.
Of the one's I've had which I bothered measuring when I first started getting them (about 50 out of various batches bought over a year), the great majority were 2.90V+/-20mV.
Equally, the XP-G2 graph is at 85°C, which would seem to drop the Vf by about 100mV from the 25°C value.

(Having a quick run through ~40 each XP-G and XP-G2 I have at the moment, that seems to pretty much hold - the XP-Gs hover around 2.90V, +/-50mV with the XP-G2s all being in the range 2.84-2.89V)

For a given LED, does the shape of the current-vs-Vf graph typically stay the same at higher temperatures, just with a temperature-dependent voltage offset, or does the dynamic resistance change as well?


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## LowLumen (Dec 7, 2012)

The Vf difference is more pronounced in the 1000-1500mA range.


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