XLamp® CXA2530 LED
The CXA family of LED arrays can include over a hundred different LED die inside one package, and thus over a hundred different junction
temperatures (TJ). Cree has intentionally removed junction-temperature-based operating limits and replaced the commonplace maximum
TJ calculations with maximum ratings based on forward current (IF) and case temperature (Tc). No additional calculations are required to
ensure that the CXA LED is being operated within its designed limits. LES temperature measurement provides additional verification of
good thermal design. Please refer to page 2 for the Operating Limit specifications.
There is no need to calculate for TJ inside the package, as the thermal management design process, specifically from TSP to ambient
(Ta), remains identical to any other LED component. For more information on thermal management of Cree XLamp LEDs, please refer to
the Thermal Management application note. For CXA soldering recommendations and more information on thermal interface materials
(TIM), LES temperature measurement, and connection methods, please refer to the Cree XLamp CX Family LEDs soldering and handling
document. The CX Family LED Design Guide provides basic information on the requirements to use Cree XLamp CXA LEDs successfully
in luminaire designs.
To keep the CXA2530 LED at or below the maximum rated Tc, the case to ambient temperature
thermal resistance (R_c-a) must be at or below the maximum R_c-a value shown on the following
graph, depending on the operating environment. The y‑axis in the graph is a base 10 logarithmic
As the figure at right shows, the R_c-a value is the sum of the thermal resistance of the TIM (R_tim)
plus the thermal resistance of the heat sink (R_hs).
Ta = 25 °C
Ta = 55 °C
Ta = 85 °C
Ta = 105 °C
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