Osram Oslon Boost HX

EasyB,
Can it fit to 17mm diameter? Can I cut it to fit if needed? I have aluminum and copper plates as potential heat sink for resistor and when I merge everything with potting compound it will look like it is made from one piece and whole driver should act as a heatsink.

But if it generates serious heat at 5A (more than 60 celzius) that could be problem…

The extra heat is not large compared to the total heat from the LED. The risk is that if the resistor you choose is too small or not heat sinked enough it will burn up. You will have to look for resistors that will fit in your lights.

Can you link me some kind of big but no to big resistor that could be bent into 17mm diameter please. I really don’t know what to order? Pretty please… :innocent:

Use a square file, only cuts out the necessary corners.

Anyone have any leads on this chip yet? Seems impossible to find, but some people have gotten their hands on it.

I haven’t heard anything about it, but apparently they have another boost family emitter 0.5mm² named HM I think.

Ooo

Okay, so the ‘boost HX’ is basically the 2mm² white flat with a 4040 footprint.
So the 1mm² white flat with 4040 footprint will probably beat it in throw (like with the 3030 sizes)?

@Jerommel
Yes. Boost line seems to take a given chip and move it up one package size/class. This probably didn’t mean much for the 1mm² chip but should for the 2mm² . Where 1mm² saw a ~10% “boost” in current handling, I would expect 15-20% for the 2mm² . This might close the gap entirely between these two. The choice between would then be based on your host/driver/runtime restrictions.

@Fat_Controller

Interestingly the If vs Vf curve maxes out at 8A (despite 6A rating)! That should mean we have a bit of overhead there I would imagine…

EDIT: Looking at the datasheet for the 1mm² (Boost HL) it appears they did the same thing. If vs Vf goes up to 4A and max rating is 3A. If overhead is proportional then the HX should be good for 12A. We’ll still just have to see if the HX ever shows up.

PS: Interesting to note as well, the HL product page notes it’s “not for new designs”. I wonder what why? Is there a successor already?

I guess vinh/skylumen found some so we will know soon enough I’m sure

Yes, Vinh and L4P have some already. .5 mm² variant is exciting news :slight_smile:

I could not find the Boost HX on L4P’s website. Vinh definitely has it though. He just posted a pic of it.

Here’s the data sheet for the Boost HM (0.5mm²)

KW_CELMM1.TG

https://www.mouser.co.uk/pdfDocs/KWCELMM1TG_EN.pdf

Well hopefully he provides some test data or can lend a fellow member with the equipment one soon. Very curious if the 4040 Boost footprint allows the 2mm² to achieve the ~5.5A/mm² like its smaller brethren. Or at least close the gap.

Speaking of which, I really wonder how much the rectangular geometry is a functional design aspect allowing the larger die to reach such high current density. Please excuse my lack of knowledge here but is there a flow of current along the surface plane of the chip? Does anyone here have expertise in this area?

No idea really, but if it was all the same, i think we would have many round die power LEDs on the market.

Oh, i thought it was more than 10 % more current for the 1mm², but it makes sense that it will do more for the 2mm²

Well circles, in general, create processing challenges in all kinds of industries. Radii are just harder to deal with than perpendicular lines (again, generally).

I’m coming at this question/idea from a uneven current distribution caused by series resistances. This is the only reason I can intuit - other than tolerance stack up on defects - that there is a decrease in peak current density as dies get larger.

I know older generation CREE leds used to use grid style current spreaders, then they turned into arrays of dots (vias?). I’m assuming those aren’t used anymore with flip chip designs, either that or they just aren’t visible anymore? I guess it’s time I learn me up on some ol’ semiconductor anatomy.

He doesn’t sell them yet, but he said he had samples. And offered some as a prize in the current OL Contest.

The thermal pad is far smaller than any 3030 or 4040 LED.
Its overcurrent performance will be absolutely crap.
There is a reason we are using CULNM1 / CSLNM1 in flashlights and not the CELNM1.
U = 4040
S = 3030
E = 1915 (1.9mm x 1.5mm)
And that’s just the package size, the thermal pad is only a fraction of that.

Yeah the 3030 1mm^2 white flat already beats it in throw, and the 4040 1mm^2 white flat beats the 3030 one.
My CSLNM1 reached 335cd/mm2 at about ~5.5A while the CULNM1 peaked at 349cd/mm2 at ~6A
This was using an LX1330b which overestimates the cd for cool white LEDs, but the point is the relative difference, the 4040 one is best.

0.5 mm² will be good for the smallest lights where even 1mm² is too large. Think Lumintop GT Nano with a shorty tube. That’s what got me excited.
It would also be good in small multi-LED lights, but only for those of us who pick sustained performance over turbo.
You’re right, the thermal pad is just too small and it doesn’t look like a good choice for absolute throw records.