SPEC NO: DSAI6704

REV NO: V.1

DATE: AUG/26/2008

PAGE: 7 OF 12

APPROVED: WYNEC

CHECKED: Allen Liu

DRAWN: S.P.Chen

ERP: 1212000024

3.2x2.8mm SMD LED WITH CERAMIC

SUBSTRATE

Heat Generation:

1.Thermal design of the end product is of paramount importance.Please consider the heat generation of the LED when making

the system design. The coefficient of temperature increase per input electric power is affected by the thermal resistance of the

circuit board and density of LED placement on the board ,as well as other components. It is necessary to avoid intense heat

generation and operate within the maximum ratings given in this specification.

2.Please determine the operating current with consideration of the ambient temperature local to the LED and refer to the plot

of Permissible Forward current vs. Ambient temperature on CHARACTERISTICS in this specification. Please also take

measures to remove heat from the area near the LED to improve the operational characteristics on the LED.

3.The equation ① indicates correlation between Tj and Ta ,and the equation ② indicates correlation between Tj and Ts

Tj = Ta + Rthj-a *W ………

①

Tj = Ts + Rthj-s *W ………

②

Tj = dice junction temperature: °C

Ta = ambient temperature:°C

Ts = solder point temperature:°C

Rthj-a = heat resistance from dice junction temperature to ambient temperature : °C/ W

Rthj-s = heat resistance from dice junction temperature to Ts measuring point : °C/ W

W = inputting power (IFx VF) : W