Audi headlight driver board teardown

In the automotive industry, Audi is renowned as the "lamp manufacturer." This reputation comes not only from the futuristic and avant-garde design of its headlights but also from the extreme complexity and high reliability of their internal optoelectronic systems. Therefore, Non-network will disassemble an Audi headlight driver board to see what hardware solutions lie inside.

A quick overview of this LED driver board, named "LED Leimo Max," which likely refers to a matrix LED headlight system (feel free to comment if you know more about this), designed and manufactured by Mitsubishi Electric of Japan.

Teardown

The sealing of this Audi LED driver board is excellent, so the disassembly is largely destructive, even causing some deformation to the PCB.

Fortunately, the onboard components can still be identified.

The control core of the driver board is a Renesas Electronics MCU, model number UPD70F3548AM1, a 32-bit automotive-grade chip that integrates rich peripheral interfaces. It interprets commands from the body domain controller, executes complex lighting algorithms, and monitors fault feedback from the driver chips.

STMicroelectronics high-side driver, model VND5E160J, features high integration with built-in power MOSFETs and comprehensive diagnostic and protection functions, including short-circuit protection, over-temperature protection, over-voltage clamping, and load current limiting. The VND5E160J is a dual-channel device suitable for driving different types of LED modules.

Texas Instruments operational amplifier, model LM2904-Q1, is highly likely used here for current sense signal amplification and conditioning, converting it into a voltage range suitable for the MCU's ADC sampling, thereby enabling precise closed-loop control of LED currents.

Rohm fast recovery diode, model RFN3BM2S; Rohm dual N-channel power MOSFET, model SP8K41FRA;

ON Semiconductor N-channel MOSFET, model NVMFD5C668NL;

Diodes Incorporated MOSFET, model 55N03L;

Now looking at the other side of the PCB:

STMicroelectronics automotive step-down switching regulator, model A7985A. It steps down the higher voltage from the vehicle battery to a lower voltage required by subsequent circuits. The chip features a wide input voltage range of 4.5V to 38V and an output current capability of 2A, effectively handling the transient surges in automotive electrical systems, providing stable power to the MCU and sensors.

STMicroelectronics also includes a high-side driver, model VN5E025A, which supports analog current sensing for precise load status monitoring—critical for systems requiring real-time headlight health diagnostics.

NXP CAN transceiver chip, model TJA1051T/3C, used for communication across the vehicle network.

Summary

From this teardown of the Audi LED driver board, we can deeply appreciate that behind the "lamp manufacturer" reputation lies not merely an array of LEDs but deeply integrated intelligent hardware. This seemingly ordinary PCB brings together the Renesas MCU, STMicroelectronics intelligent high-side drivers, ON Semiconductor and Rohm low-impedance MOSFETs, Texas Instruments precision analog chips, and NXP CAN network interfaces. Audi's supply chain choices exemplify typical "German engineering rigor"—prioritizing Tier-1 vendors with long-term automotive-grade validation. In particular, the use of intelligent high-side drivers with diagnostic capabilities, rather than cheaper discrete solutions, increases BOM cost but greatly enhances system fault diagnosis and safety. As automotive E/E architectures evolve toward domain controllers, the MCU logic functions of such driver boards may be further integrated in the future. However, the power driver and analog front-end sections, due to their direct connection to physical loads, will persist as the end points of intelligent actuators, continuing to evolve toward higher efficiency, greater integration, and smarter diagnostic capabilities.