Managing heat in power LED systems for optimal performance
When designing a solid-state solution with power LEDs, one cannot underestimate the importance of the thermal system design, as encapsulated in the phrase “Think Thermal First”. Rudi Hechfellner explains.
Temperature has a direct impact on optical and electrical performance as well as on the overall quality and reliability of an LED-based product. Therefore, it is critical that engineering teams understand the system’s thermal parameters, and focus on thermodynamic competencies.
These parameters are all interconnected. For example, a higher drive current should increase the light output of the LED. However, the higher current increases the dissipated power, causing heating within the LED, which has a negative impact on light output. Also, conversely, a higher junction temperature (caused for example by a higher ambient temperature) causes a reduction in the LED’s forward voltage, reducing the dissipated power for a constant-current source.
This article was published in the April 2009 issue of LEDs Magazine.
To read the full version of this article, please visit our Magazine page, where you can download FREE electronic PDF versions of all issues of LEDs Magazine.
You can also request a print copy of LEDs Magazine (available by paid subscription) and sign up for our free weekly email newsletter.