All along, the car lights with the development of the car and continue to evolve, especially under the intelligent trend of cars, car companies pay more attention to consumer demand, is committed to providing intelligent, personalized and more intimate service, the car lights as the eye-catching parts in the vehicle, has been given more expectations. The innovative design of automotive LED headlights, as an indispensable component of vehicles, performance is not only directly related to night driving safety, but also reflects the level of vehicle design and quality of an important symbol. The trend of software-defined vehicles and the popularity of automotive Ethernet provide a new idea for the design of E/E architecture in the field of vehicle lights.

Automotive LED matrix headlight module "benchmarking" scheme
     At the recently concluded PCIM Asia, onsemi's booth demonstrated the high-performance automotive matrix headlight solution launched by the United Nations World Ping Group. On's latest generation Boost-Buck headlight LED driver IC NCV78964 provides two Buck outputs up to 60V/1.6A to drive LED light strings and support PWM dimming. Among them, Boost as a stable voltage source, can guarantee the accumulated voltage drop requirements of multiple LED lamp strings, while Buck as a stable current source, directly drive LED light, because the current source is not affected by load voltage transients, can achieve fast switching, in the adaptive high beam matrix/pixel lamp group, has a very good performance.

    According to the relevant person in charge, the program has SPI programmable capability, so the flexibility is very high, allowing the expansion of the design to use more LED strings, and the replaceable LED driver modular design is to provide flexible product options for application deployment, such as if a single lighting module requires more than 2 LED channels, It can be combined with multiple NCV78964 or NCV78763 devices to significantly accelerate the design cycle and reduce engineering overhead costs.

    LED bead control is based on ON Pixel drive controller NCV78343 chip, designed for automotive dynamic lighting applications, especially high-current leds, with open circuit, short circuit and overvoltage diagnostic protection functions. Each NCV78343 can achieve 1-12 light beads independent on-off and PWM dimming control, and multiple NCV78343 pieces can be combined to achieve more independent control of light beads.
    The motor drive of the matrix headlamp is controlled by ON Semiconductor NCV70517 as a microstepper motor driver.
    The NCV70517 is connected to an external microcontroller via an I/O pin and SPI interface, uses a proprietary PWM algorithm for reliable current control, meets automotive voltage requirements, and has safety monitoring features such as electrical errors, undervoltage or junction temperature rise, the chip alerts.
    As an advanced automotive matrix headlight LED module, the solution meets the automotive industry's highest functional safety standard ASIL-D, which means it is more reliable in complex driving environments, and the LED driver chip NCV78964 uses dual phase boost technology. It not only improves energy efficiency, but also effectively reduces electromagnetic interference (EMI) and current ripple at the battery end, making the vehicle more energy-efficient and quiet during operation, and the flexible E/E reference design allows manufacturers to customize according to their own needs, ensuring that the product can be better integrated into the design of various models. It can greatly enhance the competitiveness of joint ventures and foreign automobile brands, and is an ideal choice to improve the quality of automotive lighting systems.
    In addition, the solution has complete design considerations for the headlamp ECU functional safety and low power consumption requirements, among which the NCV68261 is an ideal secondary tube controller with high side drive from ON. In addition to providing complete headlamp ECU protection functions such as battery overvoltage, reverse voltage and reverse current, You can also turn off the power supply of the LED driver IC and the lamp bead control IC to meet the needs of the low-power function.

From the ECU to the "headlight domain", automotive Ethernet is limitless
    In fact, in addition to the intelligent change of the car reflected in the cool light and shadow of the headlights, with the increasingly significant trend of software-defined vehicle SDV, the various functions and services of the vehicle are realized through software, which requires that the vehicle must have high-speed and stable data transmission capability. Although the traditional vehicle network such as CAN has played an important role in the past, it has been unable to meet the needs of future intelligent vehicles in terms of data transmission rate and bandwidth, and automotive Ethernet is not only a bridge connecting the nerve center of various parts of the vehicle, but also an indispensable communication technology support to promote the automotive industry to intelligent and connected transformation.
    At the PCIM Asia site, ON's other automotive LED solution in addition to the built-in LED driver NCV78964 and pixel controller NCV78343, more importantly, the use of 10BASE-T1S to achieve precise control of automotive headlights. Together, these components form a highly integrated headlight control system that enables area control through the ECU-Light architecture, including the fact that each light function can be controlled through a graphical user interface (GUI), providing a highly flexible headlight configuration, which means that vehicle manufacturers can design more personalized and diverse headlight systems. To meet the needs of different models and driving conditions. At the same time, the diagnostic information of the LED driver can be read regularly, ensuring that the system always maintains optimal performance.

    Automotive Ethernet 10BASE-T1S can provide more efficient data throughput and more determined latency, and every node has a fair opportunity to participate in the communication, providing a solid foundation for the implementation of multiple high-resolution displays in the car, advanced driver assistance systems, real-time remote diagnostics and other functions. It also facilitates seamless integration of subsystems within the vehicle and supports future OTA updates, enabling continuous upgrades and optimizations throughout the vehicle's life cycle.

    On experts stressed that the biggest highlight of the solution is that the entire automotive headlight system architecture responds to and conforms to the trend of SDV, and realizes the automotive Ethernet of each node, such as the "last kilometer" on the regional architecture of the headlight system. This means that both control instructions and data transmission can be realized through the unshielded twisted pair automotive Ethernet, ensuring that every link from the central processing unit to the end actuator can be efficiently and reliably exchanged data, not only simplifying the wiring structure in the car, but also greatly improving the overall system response speed and the ability to work together.
    There is no doubt that with the continuous progress of technology, automotive LED lighting is not only becoming more intelligent, but also playing an increasingly important role in energy saving and environmental protection, improving driving safety and comfort, whether it is from the hardware level of LED system drive design, or 10BASE-T1S technology and advanced automotive E/E architecture applications. Are promoting the automotive lighting technology towards a more efficient and intelligent direction, but also make the car more intelligent and more environmentally friendly.