Most people are not aware of how important LED drivers are to providing the adaptability and variety we have become accustomed to in today’s advanced automotive lighting systems. In the rapidly evolving automotive lighting segment, LED drivers are providing ever more comprehensive options, allowing vehicle OEMs improved energy savings, visibility safety advantages, vehicle ambience and a consumer “wow” factor not available in vehicles just a few years ago.
The key function behind an LED driver is to regulate the power output. LED drivers provide a constant light output, meaning a steady supply to the LEDs, despite possible power variations. There is, however, a misconception that LED driver technology is a “one size fits all” solution. The reality is that there is no such thing as a “universal” LED driver. Every application is unique and requires a unique driver design. Remember, the design and quality of the LED driver has a significant impact on the performance of the individual or LED string.
With LED drivers, you can choose a variety of power supply options to achieve optimal efficiency. Designers have the ability to choose various configuration options, as well as provide adjustability for items such as soft start or emergency light functions.
When selecting an LED driver it is important to consider the following five factors to determine the best fit for your application:
1) Total LED power per function: this is the key to determining LED driver topology.
2) Ambient temperature of the electronics : For example, with rear lighting where brighter LEDs are required, a linear driver is not the best option because of its high power dissipation; instead, a switching driver is a better choice because it is more efficient and, hence, runs cooler at higher power levels.
3) Flexibility to change LED configurations: light adjustment capabilities by using multiple luminance methods such as voltage reference control and PWM control. A wide operating supply range allows configuration of power supply and number of LEDs to drive.
4) Supported features: such as auto dimming, individual LED control, color change.
5) Supported diagnostics and safety compliance: such as thermal warning, thermal shutdown, open circuit, short, over-current protection, single LED failures, under voltage and overvoltage on booster, LED temperature monitoring.