trademarks of Cree, Inc.

11

xlAMP xP-c lEDS

thermal desiGn

The maximum forward current is determined by the thermal resistance between the LED junction and ambient. It is

crucial for the end product to be designed in a manner that minimizes the thermal resistance from the solder point to

ambient in order to optimize lamp life and optical characteristics.

White, royal blue, blue

Green

0

100

200

300

400

500

600

0

20

40

60

80

100

120

140

160

Ambient Temperature (ºC)

Rj-a = 15°C/W

Rj-a = 20°C/W

Rj-a = 25°C/W

Rj-a = 30°C/W

Thermal Design

XPC

Relative Intensity vs. Current (Tj = 25ºC)

GRAPH 8a

Green

0

100

200

300

400

500

600

0

50

100

150

200

Ambient Temperature (ºC)

Rj-a = 15°C/W

Rj-a = 20°C/W

Rj-a = 25°C/W

Rj-a = 30°C/W

0

100

200

300

400

500

600

0

20

40

60

80

100

120

140

160

Ambient Temperature (ºC)

Rj-a = 25°C/W

Rj-a = 30°C/W

Rj-a = 35°C/W

Rj-a = 40°C/W