Comparison Among Power LEDs for Automotive Lighting Applications

The first LED diode was created in 1969. Since then, they have been experiencing a continuous improvement in luminous efficiency and power dissipation, achieving current AIInGaP and InGaN devices for yellow to red, and blue to green, including white, colours respectively. The improvement experienced in both luminous efficiency and power dissipation makes them interesting for lighting application in automotive industry, where the advantages offered are numerous, from a lower time response in brake lights to an operating life much higher than that of the vehicle itself [1], [2]. In the other hand, the improvement experienced in luminous efficiency and power dissipation allows the construction of most of the signal devices using just a few emitters [1]. Due to the points stated above, a comparison among the most efficient red, amber/yellow and white Power LEDs currently available from the leading manufacturers is proposed, offering a comparison in terms of luminous efficiency in nominal test conditions, thermal resistance between the junction and the slug and also giving a comparison about the performance depending on junction temperature between the two most efficient LEDs for each colour.