XR-E in R5 ?

[Nake]

Has Cree stopped further improvement of the XR-E? I don't know how their manufacturing process works, just wondered if somebody knows or can speculate. I would like some XR-E in R5 for lights I have.

 

[Nitroz]

Dunno? I sure would like to know where I can but the newer, smaller die XR-Es though. Anybody?

 

[qwertyydude]

You know I did notice that my newer X-RE's seem to have a smaller apparent die size, I thought it was just me.

 

[saabluster]

You know I did notice that my newer X-RE's seem to have a smaller apparent die size, I thought it was just me.

Where did you get them from?


Hey that makes 2000 posts for me.

 

[Marduke]

The newest XR-E's use the smaller EZ900 die instead of the EZ1000 die.

 

[bshanahan14rulz]

random non-labeled bin Crees that come in flashlights at DX seem to have them. Dunno about a reliable source, though...

 

[nanotech17]

i really dislike the EZ900 die.

 

[bshanahan14rulz]

I like that it provides reasonable brightness and a smaller image, but I wouldn't mind getting the same lm/mm^2 with an ez1000

 

[znomit]

i really dislike the EZ900 die.

Why?
It should throw slightly better than a 1000 given the same bin.

To the OP, Cree no longer list even R2 in XR-E. So officially they don't exist. No new XR-E bins for two years now. :duh2:
http://www.cree.com/products/pdf/XLamp7090XR-E_B&L.pdf

 

[Nanomiser]

I got a sample batch of XREWHT-L1-WH-R2-0-01 from Cree a while back, but I can't find any specs on them now. I noticed that the R2 has been transferred to the much smaller XP-E form factor now.

Can anyone tell me what the Vf on the above bin label is or where I can find specs?

In the context of heat sinks I can't remember if XR-E Crees are electrically isolated or not?

If all else fails I guess I'll give Cree a call on Monday.

 

[znomit]

Can anyone tell me what the Vf on the above bin label is or where I can find specs?

Cree don't bin on Vf so could be anything in the usual range.
Specs at cree.com though I think they quote not more than 3.7V@1A and its usually somewhat less nowadays. 3.5 would be my guess.

 

[Nanomiser]

You are correct! I was not paying attention to the bin code format.

The XREWHT-L1-WH-R2-"0"-01 is the designator for the Forward voltage on amber, red-orange and red only and appears to have nothing to do with white.

I have answered my own question on electrical isolation. As I recall the XR-Es will need an anodized heat sink.


BTW I really like your bike light designs; thank you for sharing them. :thumbsup:

 

[Nake]

I have answered my own question on electrical isolation. As I recall the XR-Es will need an anodized heat sink.

If you clip the corners of the base so the bottom contact strips do not connect to the top ones, it will be isolated.

 

[Christexan]

If your design isolates the thermal pad from the circuit connections, then you are fine (the thermal pad is electrically neutral, if you only had one LED, you could actually connect the thermal pad to either lead connection and only isolate the 2nd lead connection.

In other words, you could put the entire copper PCB circuit leading to (or from) the LED as one flat "pad" for the entire LED (to aid heat dissipation) except for one of the two corner leads, which would improve thermal dissipation if only a PCB surface is used. Not saying you should do this, but the thermal pad doesn't care if it's part of one side of the circuit or not.

Luxeon and SSC LEDs are different, their pad is NOT electrically neutral, meaning it should be kept separate from ANY part of the circuitry. There is a direct electrical path from the pad to the LED substrate, and so it should always be fully isolated from either end of the circuit.

And what Nake said is also true, if you are only using the top connections, then trimming or filing the bottom connectors resolves any isolation issues.

Hope that helps some

 

[Nanomiser]

Nake & Christexan,

Thank you for the explanations. :thumbsup:

So by simply clipping or filing the edges of an XR-E you would sever the electrical connection between the top and bottom pads thereby isolating them.

This is a very interesting and useful tip. I guess I need to spend a little time with my DVM and an XR-E to make sure I've got it straight.

Now if I would just build my lights instead of collecting parts I might learn some of this stuff on my own.