The LED makeover for automotive exterior lighting
July 05, 2017
Car OEMs and Tier 1 firms invest a lot of effort to achieve low electromagnetic interference (EMI) in exterior lighting applications where numerous LEDs are located in a densely concentrated area....
Car OEMs and Tier 1 firms invest a lot of effort to achieve low electromagnetic interference (EMI) in exterior lighting applications where numerous LEDs are located in a densely concentrated area. Moreover, switching these LEDs at high speeds can cause overshoots and undershoots in the current. Therefore, design engineers usually have to make a trade-off between fast LED switching and low EMI.
Maxim Integrated claims its new LED controller solves this LED matrix design dilemma. Its MAX20078 synchronous buck LED controller offers both fast response time and low EMI for exterior lighting systems. A low EMI means that designers don’t require compensation components, and that simplifies the lighting design. The ultra-fast LED switching facilitates smoother transient responses and boosts overall performance.
[Maxim Integrated's LED controller for exterior automotive lighting also features fault protection and monitoring circuitry.]
The high-brightness LED controller also boasts a wide dimming ratio and allows programming the switching frequency for greater flexibility in front-lighting designs. The LED chip allows switching frequencies from 100 kHz up to 1 MHz.
Adaptive front-lighting system
Another notable effort for creating smart and high-resolution LED headlights comes from an industry collaboration comprising of German firms such as Infineon, Osram, and automaker Daimler.
As mentioned previously, in automotive exterior lighting, several LEDs are placed side by side and on top of each other due to space constraints. Then, there are additional components that switch light segments on and off. The German industry alliance has integrated electronic activation of LEDs inside the controller chip. That significantly improves the lighting resolution in a limited space available for the exterior lighting.
[Osram has developed an LED module for the smart lighting system that prevents glare for the road users while still illuminating the vehicle surroundings.]
The collaborative work has also led to the creation of an intelligent lighting system that can adapt according to the traffic situations. The sensors in the vehicle analyze the surroundings. Next, the intelligent LED driver circuitry in the controller chip sorts out the optimum level of lighting resolution according to road circumstances at that particular time.
That allows drivers to see more clearly, and they don’t have to constantly manage the range of the light beam in changing road conditions. Furthermore, the smart dimming feature ensures that headlights don’t dazzle the oncoming drivers in situations where high-resolution lighting isn’t required.