LUXEON Altilon Datasheet DS66 20130320

5

Typical Luminance Performance

Typical luminance is calculated based on the total lumens emitted from the smallest rectangle covering the optical source. This method accounts for

variations in chip and phosphor placement as well as spacing between discrete chips. Figure 1 below indicates the orientation used to determine the

source area used for luminance calculations.

For the 1x4 configuration, the typical X and Y dimensions are 4.51 and 1.06 mm, respectively.

For the 1x2 configuration, the typical X and Y dimensions are 2.21 and 1.06 mm, respectively.

Typical Use Condition Matrix—Relative Flux

Normalized to T

The graphs on the next page predict the relative flux under various use conditions normalized to the test conditions of 1000 mA pulsed operation

(20 msec pulse) at case temperature of 25°C. These graphs can be used to determine the effects of case temperature and forward current on the

values of minimum and typical flux to define performance at the expected use condition. For example:

Given a flux at T

c

= 25°C and 1000 mA (20 msec pulse) of 700 lm for 1x4 configuration, the flux value under different conditions can be predicted.

If expected use condition is 700 mA at T

c

= 100°C, the relative percentage of flux would be approximately 70% of the reference value.

Hence, the predicted flux at 700 mA and T

c

= 100°C: 700 lm x 0.7 = 490 lm.

Y

Figure 1. Area surrounding optical source for luminance measurements.