Along with the continuous improvement of LED brightness, LED is widely applied in automotive lighting, which also drives the usage of power MOSFET in the automobile industry. This article will introduce the current situation of LED applied in automotive lighting and relevant solutions for you.
Automotive applications with overall adoption of LED lighting
LED lighting is a trend and an application with rapid growth in the automotive field. Compared to standard bulbs, LED was initially seen as a decorative upgrade for most high-end cars. However, it is now treated as clear way toward energy conservation and emission reduction because it can save more power. Due to its simple system integration ability and the characteristic of being easy to control, it only needs low rate of beam effect form to constitute the basic element of beam forming. In addition, LED can also be applied in animal and pedestrian detection system in Advanced Driver Assistance Systems (ADAS).
In the application of automotive lighting, LED can be mainly divided into the front LED, rear LED and interior LED lighting. The front LED lighting is the most current consuming application with high complexity, requiring a lot of innovation in this field. Engineers usually choose a multichannel boost/back topology to provide flexibility for LED drivers. For the rear LED lighting application, it requires medium power and lower complexity than that of front LED lighting. For the interior LED lighting application, it is mainly based on the functional and aesthetic requirements, which uses less power and only basic controllability is needed.
The requirements of the front LED lighting are high power, high voltage, high controllability and high frequency with the function of dimming. Conducting boost/buck repeatedly during DC-DC conversion, the main applications of it include high beam, low beam, turn indicator lamp, fog lamp, daytime running lamp and spot light. The requirements for the rear LED lighting are medium power, high voltage, high controllability and boost DC-DC conversion, which is mainly applied in stop indicator lamp, position indicator lamp, fog lamp and turn indicator lamp. The interior LED lighting requires low power, low voltage, current control, Pulse Width Modulation (PWM), which is mainly applied in door open indicator lamp, reading light, dash board, gear shift indicator lamp, door module light, glove compartment light etc.
Compared with other electronic applications, the application environment of automobile is more complex, which requires higher power stability, electromagnetic interference, vibration and temperature etc. The number of semiconductors applied in automobiles increases gradually, which is almost twice the growth rate of car production. Thus, it results in the need for more complex Engine Control Units (ECU). Along with the increasing number of electronic components, it will directly affect the objectives of Electro Magnetic Compatibility (EMC). Therefore, shorter cables will be required for electronic components, of which component density will be improved for the parts near the engine and higher thermal performance and the packages with high power density will be adopted.
New model automobiles have increasingly higher requirements for braking, power steering and engine management, which must comply with the specification of AEC-Q100/-Q101 as well as pursue the goals of quality, excellent design and zero defect. In addition, in order to cooperate with the application of LED in the automotive field, the silicon chip also needs to develop with the trend of miniaturization. Taking Nexperia Company as an example; in order to enable customers with higher productivity, Nexperia constantly innovates in the power MOSFET silicon chip technology and strives to reduce the RDSon per square area. BUK7208-40B MOSFET, for example, the one adopts 8mΩ n channel with DPAK (10 mm x 6.5 mm) package has been gradually eliminated due to the reason that the current 8mΩ MOSFET like BUK7M8R0-40E adopts smaller package of LFPAK33 (3 mm x 3 mm), which is relatively new with lower MOSFET cost and even cheaper than the big and outmoded MOSFET package.
In the application of the front LED lighting, it is required to adopt the solution of high-brightness multi-LED driver with high efficiency, digital control self-adaption glare-free function and LED control with separate dimming function. The entire solution must have accurate LED current control, compact design, high efficiency driving program design and low cost, which must adopt low EMI solution with small scale highly integrated packaging technology.
In the application of the rear LED lighting, the VBAT with independent brightness output and high efficiency is needed for the market requirement, of which the constant brightness output can be achieved through accurate current control. The total solution must have a compact design, high efficiency power conversion and low cost with small scale highly integrated packaging technology, low EMI and sensitivity as well as the design of high temperature resistance.
The market requirement for the interior lighting application includes single channel, dual channel and multichannel LED drivers and constant current LED driver with compact design, which adopts a serial interface to reduce the number of interface lines and cost-benefit system solution with non-leaded package to reduce EMI and EMC.
Observing the rapid development of LED automotive lighting application, Nexperia Company has launched MOSFET and logical solution that can coordinate with relevant applications, and continues to devote itself to the improvement of quality procedure and process. The products launched by Nexperia go far beyond AEC-Q100/-Q101 standards, which can provide more than twice the quality cycle time. Strict attention is paid to the details and the commitment for automotive quality have provided higher yield for the production line and field of automotive industrial customers and gained multiple quality awards issued by the strictest customer with 0-kilometer failure rate.