AppNote180130 - CCT Approximation for VR16SP4 MCPCB and beam shape for various CCT.

A simple Excel sheet to help determine the resultant color temperature when several different E21A used.

Download here


Case study of mixing 2000K (sm203), 3000K (sm303), 4000K (sm403), and 5000K (sm503) with flux rank D160, D200, D220, and D220 in the same order. The calculated CCT is 3625K.  From the picture below the resultant CCT can be seen in between 3000K and 4000K (rightmost picture). Fairly accurate.


Please note that the test was done using 3 steps MacAdam binned LED which is the tightest binning for this particular LED. 5 and/or 7 steps MacAdam binned LED will have broader range (less accurate result).

Beam shape for various E21A CCTs

Beam pattern under any optics (reflector, lens, or TIR optic) differs depending on the CCT. As can be seen from the picture above, the warmer the CCT the narrower and more defined the hot spot becomes. This is due to the "shrinkage" of illuminance area for warmer CCT (warm CCT has thicker phosphor layer than it's cooler variants hence less light exiting the phosphor layer). Higher CRI also tend to produce smaller hotspot because of the same reason. This fact follows Nichia's data. Below is the overlaid pictures of Nichia NV4x144Ax (blue line), NVSx219C (red line), warm white NVSLWE21A (orange line), and cool white NVSWE21A (light blue line) radiation angle distribution.



Share on Facebook
Share on Twitter
Please reload

Recent Posts
Please reload

Please reload


©2020 by Clemence R&D [CRD]