Copyright © 2008-2010 Cree, Inc. All rights reserved. The information in this document is subject to change without notice. Cree, the Cree logo and XLamp are registered trade-

marks of Cree, Inc.

8

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, Blue,

Royal Blue

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

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