LEDs Illuminate New Automotive Designs
Superior performance, longer lifespans, efficiency, affordability, and design flexibility makes LEDs the obvious choice for most automotive lighting applications, from headlights and taillights to interior ambient lighting, indicators, and controls.
One of the most visible advancements in automotive design can be spotted from a mile away: LED lighting is now in widespread use in vehicles from every maker. Introduced mainly in luxury brands in the 2000s, light emitting diodes (LEDs) and organic LEDs (OLEDS) have advanced so profoundly that their superior performance, longer lifespan, efficiency, affordability, and design flexibility makes them the obvious choice for most vehicle lighting applications, from headlights and taillights to interior ambient lighting, indicators, and controls.
LED lighting brings greater vision and visibility to vehicles and enables automakers to differentiate their products with striking headlight and taillight arrangements and user-friendly interior lighting. Additionally, LED lighting can integrate with other electronic systems through advanced electronic control units (ECUs) and vehicle network architectures. This integration enhances lighting functionality, safety, and energy efficiency. However, automotive design is in a period of dramatic change as electrification, automation, increased in-vehicle connectivity, and connectivity between the vehicle and external entities and infrastructure challenges automakers and components suppliers to design for the future, and lighting is changing just as much as other vehicle technologies.
Additionally, standards vary widely by region, with some countries embracing specific LED lighting technologies or whole system vehicle technologies, such as electrification, while others hang back. Automotive lighting and safety regulations and standards vary between regions. In Europe, the Economic Commission for Europe (ECE) regulates automotive lighting, while in the U.S., the National Highway Traffic Safety Administration (NHTSA) oversees these regulations. Adapting LED lighting systems to meet these varying global requirements can be challenging for manufacturers.
For example, in the U.S., headlights that are blue tinted or seem to be intentionally blinding are common, while in other regions, adaptive driving beam headlights (ADB), a lighting technology that is becoming widespread, address the needs of all road users. ADB (also called matrix LED) headlights use millions of LED pixels to project light in deliberate patterns that adapt in real-time to create safer driving conditions, such as diverting intense light away from oncoming drivers to focus specifically on the lane ahead. Other new LED lighting technologies, including laser LED lighting, are just beginning to be used by high-end makers but may become more widespread. Smaller, lighter, more versatile, and more powerful interconnects are key to integrating every type of LED lighting into all levels of new automotive designs.
“We are closely monitoring trends such as new technologies like ADB and the integration of ECUs,” said Liz Yamada, I-PEX product manager. “We anticipate that these trends will drive an increase in the number of components and demand for smaller-sized components. As a result, I-PEX is focusing on further development of narrow-pitch/multi-pin connectors.”
I-PEX developed its ISH and IARPB product lines specifically to address the needs of LED lighting in automotive applications, and Tier 1 automakers have adopted the ISH for headlamps and automotive infotainment applications, while IARPB is used in automotive front, rear, and turn lights. “Both products can also be used in applications such as camera control modules and automotive battery management systems (BMS). Other than automotive use, they can serve ATVs, trucks, and factory automation equipment,” said Yamada. The company is working on the ISH18, a horizontal hybrid version of the ISH connector.
Rugged for the road
Interconnects for automotive LED lighting technologies must address the unique harsh conditions of automotive systems while anticipating new technologies. “Automotive lighting is a ‘semi-critical’ automotive component, which means that connectors must pass severe automotive testing requirements” said Garth Miller, Hirose. “Automotive lighting customers value PCB space, manufacturability, and component cost. Hirose helps with these goals by providing smaller connectors in a variety of space-saving orientations to streamline manufacturing processes. The right connectors can be assembled quicker and with more room for error. Better manufacturability means lower manufacturing overhead.”
As in military and aerospace technologies, size, weight, and power are paramount considerations for automotive electronics. Connectors must be lightweight to keep overall vehicle weight down. They also must be ruggedized against seasonal temperature fluctuations and internal heat generated by the car’s engine or battery management system. (While much cooler than traditional halogen or incandescent bulbs, LEDs still generate heat, making thermal management a concern in zones with lighting.) Automotive lighting systems must maintain signal integrity amid constant vibration and occasional shock. The ISH, for example, features embedded spring terminals to endure high vibration and enhance long-term electrical connection. For the IARPB series, the positioning boss on the housing helps to endure high vibration environments, up to 10G.
System compatibility with complex electronics and control systems are another concern. LEDs require specific voltage and current control, often needing pulse-width modulation (PWM) or other driver circuits to regulate power supply and prevent flickering. This adds complexity to the vehicle’s electrical system and requires sophisticated electronic control units (ECUs). LEDs, especially those used in headlights and adaptive lighting systems, must be fully integrated with the vehicle’s ECU, sensors, and control networks (e.g., CAN bus) in tandem with vehicle cameras, sensors, and driver assistance systems. This integration requires precise calibration and compatibility checks during the design process. Managing EMI in vehicle architectures is also crucial.
Versatile connections
“The automotive industry is currently focusing a great deal of attention on autonomous driving and safety systems, but a similar revolution is already taking place with the conversion of vehicle lighting to LEDs, which have a decisive influence on vehicle design today,” said Kai Rotthaus, Lumberg. “Multi-pole direct connectors are also the solution here for developing space-saving designs.”
Lumberg’s RAST 2.5, a classic connector used in billions of automotive designs, has been scaled down yet again to serve LED lighting systems as well as other precision electronics in vehicles. The RAST 1.5 saves 43% of space compared to the RAST 2.5 and is designed for currents up to 1 A. A significant proportion of previous RAST 2.5 connectors are used below 1 A and can now be replaced by RAST 1.5 to save space on the PCB. The characteristic RAST coding is available as well as the option of fully automated cable assembly. The weight saving due to reduced conductor cross-sections is then 40%.T his versatile connector is well-suited to high-performance LED headlights.
LED lighting is still evolving as new lighting technologies emerge and extend automotive design and integration possibilities. Through intelligent control systems, power management, and integration with safety and comfort systems, LED lighting in vehicles has become an extension of vehicle connectivity and plays a key role in vehicle safety, energy efficiency, and user experience.
To learn more about the companies mentioned in this article, visit the Preferred Supplier pages for I-PEX, Hirose Electric, and Lumberg.
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