In 2012, the market size of HB LED is expected to reach $12 billion, and by 2015, the market will grow to $20 billion 200 million, with a composite growth rate of 30.6% (data source: Strategies Unlimited). One of the key areas of LED growth is LED's use in automotive design. The application range of LED in the car includes headlights, white skyline lights, brake lights and steering signals, dashboard display and backlighting, and all kinds of inside lights. Because customers have style preferences and safety requirements, almost all new models offer LED daylight running lights (DRL). Most of the 2013 models of Honda accord use LED for daylight lights, and LED headlights for travel models and hybrid vehicles (see Figure 1). In order to maintain this amazing growth rate, LED must not only provide more reliability, lower power consumption and more compact dimensions, but also have to achieve innovative designs such as turning headlights, anti glare, and so on. In addition, in the automotive environment, all these improvements of LED must be optimized, and at the same time bear the relatively demanding automotive electrical and physical environment. It goes without saying that these solutions must also provide very flat and compact board area and improve overall cost performance.
Although LED has been used for daylight lights, brake lights, steering lights and internal lighting in recent years, the application of headlights is relatively new. At present, only a small number of cars are provided with LED headlights, including Honda accord, Audi A8 and R8, Lexus LS600h and RX450h, TOYOTA Price, Cadillac Cayre, and Porsche cayenne. Some industry estimates suggest that the LED headlight market was about $1 billion in 2012, and the market is expected to exceed $2 billion by 2014 and continue to grow exponentially.
One of the biggest challenges of automotive lighting designers is how to optimize all the advantages of the latest generation of high brightness LED. High brightness LED requires an accurate and efficient DC current source, dimming method and all kinds of protection functions. In addition, the driver IC of these LED must be designed to meet the above requirements under a variety of conditions. Therefore, the power supply solution must be highly efficient, provide solid functions and reliability, and at the same time be very compact and economical. It can be said that driving high brightness LED, the most demanding application is the automotive headlamp lighting applications, including daytime car lights and headlights, because such applications are in a harsh automotive electrical environment, which must be provided with high power, usually between 15W and 75W, and must be placed in a very limited space. To achieve all these requirements, we must maintain attractive cost structure. |
