trademarks of Cree, Inc.

11

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

Green

Pc amber

red-orange, red

Thermal Design - white

0

200

400

600

800

1000

1200

0

20

40

60

80

100

120

140

Ambient Temperature (ºC)

Rj-a = 10 °C/W

Rj-a = 15 °C/W

Rj-a = 20 °C/W

Thermal Design - royal blue, blue

0

200

400

600

800

1000

1200

0

20

40

60

80

100

120

140

Ambient Temperature (ºC)

Rj-a = 10 °C/W

Rj-a = 15 °C/W

Rj-a = 20 °C/W

Rj-a = 25 °C/W

Thermal Design - green

0

200

400

600

800

1000

1200

0

20

40

60

80

100

120

140

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 - amber, red-orange, red

0

200

400

600

800

1000

1200

0

20

40

60

80

100

120

140

Ambient Temperature (ºC)

Rj-a = 10°C/W

Rj-a = 15°C/W

Rj-a = 20°C/W

Rj-a = 25°C/W

Thermal Design - PC amber

0

200

400

600

800

1000

1200

0

20

40

60

80

100

120

140

Ambient Temperature (ºC)

Rj-a = 15 °C/W

Rj-a = 20 °C/W

Rj-a = 25 °C/W

Rj-a = 30 °C/W