introduction According to the statistics of Strategies Unlimited (see Figure 1), the market for high-brightness (HB) LEDs reached $12 billion in 2012. By 2015, the market will grow to $20.2 billion, with a compound annual growth rate of 30.6%. LEDs used to backlight displays are currently the main driver of this unprecedented growth. Applications include high-definition televisions (HDTVs), automotive displays, and a host of handheld devices. In order to maintain this amazing growth rate, LEDs must not only provide enhanced reliability, lower power consumption, and smaller/flatter form factors, but must also achieve significant improvements in contrast, picture clarity, and color accuracy. In addition, displays for automobiles, avionics, and marine electronics must maximize all of these improvements while accepting a variety of ambient lighting conditions, from bright sunlight to nights without moons. These display applications implemented by Transistor Liquid Crystal Display (TFT-LCD) include infotainment systems, meters, and a wide variety of meter displays. Backlighting these displays with LEDs has created some unique LEDIC driver design challenges because of the readability of the display under a variety of ambient lighting conditions. This requires LED drivers to provide a very wide dimming ratio and high efficiency conversion while being able to withstand the rigors of relatively harsh electrical and physical environments in automobiles. Finally, these solutions must provide a very flat, compact footprint while increasing price/performance. Figure 1: High Brightness LED Market Forecast (Source:StrategiesUnlimited) How can we support such an amazing growth potential in the automotive lighting market? First, in terms of producing light, LEDs are 10 times more efficient than incandescent lamps and almost twice as expensive as fluorescent lamps, including cold cathode fluorescent lamps (CCFLs), thus reducing the amount of light output (measured in lumens). Required electrical power. As LEDs continue to evolve, their effectiveness or ability to generate light lumens from electrical power will only continue to increase. Secondly, we are in a world that cares about the environment. When using LED lighting, there is no need to process, contact and remove the toxic mercury vapor that is common in CCFL/fluorescent lamps. Finally, incandescent lamps need to be replaced approximately every 1,000 hours, while fluorescent lamps can last for 10,000 hours, compared to LEDs that last for more than 100,000 hours. In most applications, this allows the LED to be permanently embedded in the final application. This is especially important in the case of backlighting for automotive instrumentation/navigation/information entertainment system control panels that are embedded inside the car because they will never need to be replaced during the life of the car. In addition, LEDs are smaller and flatter than other illuminators, so LCD flat panel displays can be very thin and require minimal automotive interior space. Also, by using red, green and blue LED configurations, an unlimited variety of color lights can be provided. LEDs can also be dimmed and turned on/off at much faster than the human eye can detect, resulting in significant improvements in backlighting of LCD displays while allowing for extremely high contrast and high resolution. One of the biggest challenges for automotive lighting system designers is how to optimize all the benefits of the latest generation of LEDs. Because LEDs typically require accurate and efficient DC current sources and dimming methods, LED driver ICs must be designed to meet these requirements under a variety of conditions. Power solutions must be efficient and reliable in terms of functionality and reliability while being very compact and affordable. It is reasonable to say that one of the most demanding applications for driving LEDs will be automotive infotainment systems and dashboard TFT-LCD backlighting applications, as they are in harsh automotive environments and must compensate for a wide range of ambient lighting. Conditions change and must be placed in a very confined space, all of which must be done while maintaining an attractive cost structure. Automotive LED backlighting Advantages such as small size, long life, low power consumption, and enhanced dimming capabilities have led to the widespread adoption of LED TFT-LCD backlights in today's cars, trucks, trains, airplanes and ships. LED backlighting is primarily from infotainment systems, which typically have an LCD display that is mounted in a central part of the dashboard so that drivers and passengers can easily see where they are and perform audio tuning. And various other tasks. Many newer car designs use a single dashboard to backlight all display instruments that are convenient for the driver to control, as shown in Figure 2. LED backlighting for the dashboard is often shared with infotainment systems, making it easy to read the numbers on the control panel. Similarly, many vehicles, including cars and trains, as well as LCD displays mounted behind the aircraft seats, allow passengers to watch movies, play video games, and more. Historically, such displays have been using CCFL backlighting, but replacing relatively large CCFL lamps with very flat white LED arrays to provide more accurate and adjustable backlighting and a working life that exceeds the life of the vehicle or aircraft, which It has become more and more common. Figure 2: LED backlighting dashboard There are several positive implications for using LEDs in such environments. First, LEDs never need to be replaced because their reliable life span exceeds 100,000 hours (11.5 years of service life) and has exceeded vehicle life. This allows automakers to permanently embed LEDs into the interior backlighting system without having to leave room for replacement. Because the LED lighting system does not require as much depth or area as the CCFL lamp, the style can also change significantly. In addition, LEDs are generally more efficient than incandescent lamps in providing light output (in lumens) from input electrical power. This has two positive effects. First, LEDs leak less electrical power from the car bus, and just as importantly, LEDs reduce the amount of heat that needs to be dissipated in the display, eliminating the need for bulky, expensive heat sinks. Another important benefit of LED backlighting is the wide dimming ratio capability offered by high performance LED driver ICs. Since the interior of the car is subject to a wide range of ambient lighting conditions, including every change from direct sunlight to complete darkness, the human eye is very sensitive to small disturbances in the light output, and the display needs to be adjusted accordingly. Dark or bright, so first and foremost, LED backlighting systems offer very wide dimming ratios from 1,000:1 up to 30,000:1. With a suitable LED driver IC, this wide dimming ratio is relatively easy to implement, while CCFL backlighting is not possible. Figure 3 shows an LED backlighting dashboard and an infotainment system display that shares LED backlighting. Figure 3: LED backlighting dashboard and navigation display With the continuous maturity of LED lighting technology, the automotive industry has been using LED light sources for instrument panels and interior lighting, and LED lighting is gradually capturing brake lights, fog lights, low beam lights, high beam lights, and daytime running lights. Application fields such as adaptive headlights (AFS) for exterior signal indication and headlight illumination.The challenge for LEDs to be used in exterior lighting is the need for integrated, flexible and networked drives. Automotive Pcb,Blank Circuit Board,Metal Core Pcb,Power Circuit Board Chuangying Electronics Co.,Ltd , https://www.cwpcb.com