This design balances adaptability and functionality, making it suitable for a wide range of automotive headlight applications.
A headlamp-leveling system is essential for maintaining the correct height of a vehicle’s headlight cut-off line, adapting it to the vehicle’s load condition. This adjustment prevents the blinding of oncoming traffic and ensures better visibility. Modern vehicles often employ dynamic headlamp leveling systems, which can react to changes in driving conditions such as acceleration or braking. Typically, stepper motors are used in these systems for precise control. Adaptive front-lighting systems (AFS) further enhance nighttime visibility and road safety by adjusting the headlight angle and intensity based on factors like vehicle speed, steering wheel angle, and weather conditions.
This reference design TIDA-020026 by Texas Instruments (TI) provides a comprehensive solution for driving and controlling two stepper motors in automotive headlight applications, including AFS, dynamic headlamp leveling, and curve lighting. The design utilizes a local interconnect network (LIN) system basic chip featuring an integrated 3.3-V linear voltage regulator, two stepper motor drivers with a serial peripheral interface (SPI), and a microcontroller LaunchPad™. The design supports applications such as adaptive LED driving modules and high-resolution digital light processing (DLP) modules for headlights.
The board is implemented in the BoosterPack™ format, allowing compatibility with various microcontroller units (MCUs). This format includes a simple connector interface to external LaunchPad MCU boards, facilitating code development and testing using tools like Code Composer Studio or Energia. This modular approach accelerates optimization for specific operating conditions. However, in a production scenario, the design would likely integrate the MCU and components onto a single board, reducing size and enhancing efficiency.
Key features of this reference design include support for up to 1-A motor current, CISPR25 compliance for electromagnetic compatibility, and a fully integrated solution. The DRV8889-Q1 stepper motor driver is a critical component, offering two N-channel power MOSFET H-bridge drivers, a microstepping indexer, and integrated current sensing. It can drive up to 1.5-A full-scale or 1.1-ARMS output current under optimal conditions. Additionally, the TLIN1028 LIN transceiver serves as a reliable physical layer for low-speed in-vehicle networks, with compliance to multiple LIN standards and integrated wake-up and protection features. It supports data rates up to 20 kbps, with the capability to work up to 100 kbps for in-line programming. Its modular structure and support for advanced development tools enable efficient prototyping and customization, paving the way for enhanced headlight performance and safety in modern vehicles.
TI has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
