These would hopefully enable better throw, much better cd/W than XP-G2 while having only slightly lower output. And hopefully slightly better lm/W too, though probably not.
It would throw slightly less than a quad array with a single optic of the same diameter, but be smaller and (am I right here?) put more lm in the hotspot.
I wouldn’t recommend a 2x2 array. Only odd numbers so that you can have one die in the center perfectly focused. A 3x3 would still be smaller than the XM/50.2 footprint and be factory rated at 6000 lumens 4860 lumens.
EDIT 11/28/17: semi-official max lumen specs found. Previously stated numbers where a calculated guess from other claims made previously.
Also, it should be noted that the XHP50.2 maxes out at about the same lumens when maximally driven.
Each die is rated at 650 lumens? Wow, that is impressive. Although they always seem to put space between the dies, would it still be smaller then an xhp50 die?
If so then these new dies are a lot more interesting then I first thought. a 4x4 then should be about the same as an XHP70 except with the ability to make 10k lumens with a 3V LED? Now that is an interesting prospect.
Although I worry that they will suffer the same issues as the E21 from nichia. Where they just can’t make much output in the real world due to the lack of thermal pad.
“The first product available in the new family of XD LEDs is the XLamp® XD16 LED that delivers a breakthrough lumen density of up to 264 lm per square-millimeter”
Quote from their press release months back.
1.6*1.6*264 = 675
I don’t know if that’s going to hold true or not, but that’s what they claimed to the world. That leaked data sheet that I linked though shows max power at 4W. Which would put max output closer to 500lm based on typical efficacy at rated max current for XPG3
A thought:
3x3 array, but wired to 2 separately driven groups.
Group 1 is only the central emitter.
Group 2 is the rest.
You can drive only group 1 to have a thrower or drive both for a flooder.
Would it be possible to make a good PCB for such light? If no, would cutting corners and making 4+1 enable such thing?
I think there’s a slim chance to get a white CSP LED without phosphor blanketing the sides of the die. Without the phosphor the blue light would leak without first converted to white light. I’m curious about this NX footprint.
Cree has different approach here. The NX phosphors cover the entire sides, while E21A blocking and
reflecting the side spill using white reflective material. This perhaps explain why NX produce more output. E21A has the narrowest beam among current CSPs.
Okay i am snooping around and if i am right? It is a XD16A and its a dome less LED?
Cree Extreme Density LEDs
• Lumen Density: First to deliver >200 lm/ mm2
• Optical Crosstalk: Very low
• Thermal Contact: Highest in class
• Soldering: Proven footprint design
• Handling: Very robust package
540lm @ 4.5W =120lm/W at max rating. Still pretty high. I’d say there’s still plenty of room for overdriving with that efficacy. This was a concern since these newer LEDs are getting more aggressive with their drive currents because of increasing rated operating temperature. Assuming there isn’t (which is a silly assumption) any thermal bottlenecking and sudden drop-off at higher currents, we could see 1000 lumens from this LED if it follows the typical curve. I’m trying to keep my expectations low but I’m still very excited for this LED
Clemence has been fiddling with the Nichia equivalent of these leds (the E17 and E21 series) and ran into some new problems with these (CSP) leds (burned phosfor above the gap between the solder pads, photon cross-talk between leds in a matrix) , but he also made progress in driving them at higher currents with a newly developed (expensive!) ledboard. (the Cree NX leds seem to differ from a true CSP led by that there is still a substrate under the die). So indeed keep the expectations limited until the performance in flashlights is proven.
I still don’t know the exact footprint but it won’t differ much compared to E17A or E21A (both have the same solder pads). At the very least it will fit in the VR16S1 as a single or 4p setup. It would be great if it fits in the VR16SP4.
This is not a true CSP, looks like there’s still AlN or SiC beneath the phosphor. If this is true then it would not suffer from premature phosphors overheating like those E Nichias.
