Cree bins output @ constant current, but what about lumens per watt?

Bright+

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The binning is based on lumens output at a constant current (I think its 350mA) rather than constant power. So, if there is a Vf variation in the bin, the efficiency might not follow the bin.

Does anyone know how different bins fare in lumens per watt?
 

Bright+

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That does not look right. Who created the table? The flux and lumens-per-watt holds a linear relationship in that table, which means there is zero variation allowed for Vf since 350mA drive current is already defined.

Cree datasheet shows variation allowance in Vf and efficacy is not part of the table.
http://www.cree.com/products/pdf/XLampXP-G.pdf
 

znomit

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That does not look right. Who created the table? The flux and lumens-per-watt holds a linear relationship in that table, which means there is zero variation allowed for Vf since 350mA drive current is already defined.

Cree datasheet shows variation allowance in Vf and efficacy is not part of the table.
http://www.cree.com/products/pdf/XLampXP-G.pdf

Thats the old cree roadmap for the XRE before they got stuck at R2. Flux scales with lumens per watt, yes.

Yes the current documentation just specifies minimum lumens and has a crazy huge range on the Vf of 3.0 to 3.75! In practice you wont see such large variations.
 
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