Light Control And E-Switch Reference Design

The solution controls automotive lighting and diagnostics, provides communication via LIN and CAN, and precisely manages all car lights.


Light control and e-switch systems are crucial components in modern automotive applications. These technologies ensure proper visibility, enhance safety and optimize energy efficiency by effectively managing headlights, brake lights, and turn signals. Additionally, they provide real-time diagnostics, allowing for timely maintenance and reducing the risk of lighting failures. By enabling adjustable and adaptive lighting, they contribute to driver comfort and aesthetic appeal while ensuring compliance with regulatory standards. Furthermore, these systems integrate seamlessly with advanced driver assistance systems (ADAS), paving the way for future innovations in automotive technology. The KEA128LEDLIGHTRD is a reference design by NXP Semiconductors for controlling automotive lighting and diagnosing the status of the front headlamp using an eXtreme switch.

It uses the 32-bit Arm Cortex-M0+ Kinetis KEA128 automotive-grade MCU and the MC10XS3425 eXtreme switch. The design provides a complete headlight control solution with LIN and CAN communication, covering LEDs, tail lights, turn signals, lamp current control, and diagnostics. It manages real automotive lights, including high and low beams, turning, and braking. Communication within the system is via SPI. Freescale transceivers enable LIN and CAN communication, and potentiometers control the light level and bulb status.

The system features light level control and bulb status monitoring, with communication handled via SPI throughout. It includes a light connector interface to increase the number of controlled lights and an SWD connector interface for debugging. The system has 4 LEDs and 4 potentiometers for precise control and status indication.

The Kinetis EA series of 32-bit Arm Cortex MCUs is designed for a wide range of automotive and industrial applications that demand high-quality and long-term support. Featuring a low-power Arm Cortex-M0+ core and 8–128 KB of embedded flash, the Kinetis EA series offers excellent EMC/ESD performance, high-temperature tolerance, and low radiated emissions. It provides a scalable and robust performance solution for cost-sensitive automotive applications. The series also includes a broad set of reference designs, tools, and application notes to help shorten design development and accelerate time-to-market.

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The NXP 12XS3 eXtreme Switch Generation 3 12V devices are SPI-controlled smart high-side switches that provide diagnostics for the switch, light source, and wiring harness, along with comprehensive fault management and load control without complex software. They feature programmable multi-step latched overcurrent shutdown protection, which minimizes thermal stress during overload conditions, reduces junction temperature rise, and improves reliability. Packaged in PQFN and SOICW-EP formats, these switches offer low RDS(ON) and high integration, resulting in savings in module size, power dissipation, and overall system cost.

NXP has tested this reference design. It comes with a bill of materials (BOM), schematics, etc. You can find additional data about the reference design on the company’s website. To read more about this reference design, click here.