High-power LEDs are becoming very popular in automotive exterior lighting design thanks to excellent lighting characteristics and efficiency. The electronics supporting the LEDs must in turn be fast, efficient, and accurate to control light intensity, direction, and focus. They must support a wide input-voltage range and must be able to operate outside the car radio’s AM frequency band to avoid electromagnetic interference (EMI). They must also support complex light patterns required in LED matrixes for adaptive front-lighting systems.
This article reviews a typical LED power-management solution. Furthermore, it presents a novel buck controller IC that enables a fast, efficient, and accurate LED lighting solution.
LEDs in Automotive Exterior Lighting
LEDs are taking the automotive industry by storm due to significant advantages over traditional technologies. The superior clarity of the white light in LED headlights improves driver reaction time (Fig. 1). Adaptive front-lighting systems (AFS), enabled by LED matrixes, produce fast, complex light-pattern changes that improve visibility for drivers in poor light conditions. At night, in response to the beams of an incoming car, AFS can automatically adjust the light pattern, preventing the oncoming driver from being blinded by harsh lighting.