Xiaomi YU7 LED Driver Module Teardown

In today's increasingly fierce "involution" of the new energy vehicle market, car lights have long transcended their mere lighting function to become a core carrier showcasing a brand's technological sophistication and safety prowess. The Xiaomi YU7, as the second heavyweight model under Xiaomi Auto, features matrix adaptive LED headlights. This article by eefocus will dismantle its headlight driver board.

Visually, the Xiaomi YU7 headlight driver board is exquisitely crafted. Supplied by Valeo, it is encased in an aluminum alloy shell, secured with rivets at the four corners, and sealed with glue along all four edges. Its moisture and water resistance reliability ranks in the top tier, necessitating a forceful disassembly process.

Teardown

Using a cutting machine to slice off the four riveted corners, we pried open the casing to reveal the internal main PCB.

Let's focus on the components on the PCB.

A Renesas Electronics 32-bit automotive-grade microcontroller, model R7F7015814, based on their proprietary RH850 core MCU.

An NXP automotive lighting LED driver IC, model ASL2507S.

Three Texas Instruments (TI) LED drivers, model TPS92520-Q1. These are 1.6A dual synchronous buck products with SPI. This constitutes the core power control section of the driver board. The YU7's headlights comprise multiple independent zones requiring high-precision constant current driving and PWM dimming. TI's dedicated automotive-grade LED driver chips offer extremely high channel consistency and open/short circuit diagnostic capabilities, which are key to achieving precise light pattern control.

Now let's look at the side of the PCB with the interfaces.

Two Vishay MOSFETs, model SQJ186E. Next to them are two components guessed to be diodes; the silk screen reads "100T L08E," but the specific manufacturer and model are unknown. If anyone knows, please leave a comment to let us know.

Two Yangjie Technology MOSFETs, but of different models. One is model YJG85G06B; the other is model YJG130G04C. Power devices represent a "breakthrough point" for localization, indicating that in fields with relatively mature technology and slightly lower process requirements, the domestic supply chain already possesses strong competitiveness.

A Texas Instruments (TI) buck converter, model LM63610-Q1, featuring spread spectrum, ranging from 3.5V to 36V, 1.0A.

An Infineon SBC chip, model TLE9471-3ES, an integrated circuit with a CAN interface.

Two NXP high-speed CAN transceivers, model TJA1044. Considering the YU7's high-level intelligent driving requirements, the headlights need to receive perception data in real-time (such as the position of oncoming vehicles), making high-bandwidth CAN interfaces standard. This segment remains monopolized by NXP, and domestic alternative solutions currently find it difficult to break in.

A Texas Instruments (TI) multiplexer, model TMUX1308-Q1, an automotive-class 5V, 8:1, single-channel multiplexer with injection current control and 1.8V logic levels.

A STMicroelectronics high-side driver, model VND7140AJTR.

A Texas Instruments (TI) motor driver, model DRV8889-Q1, an automotive-class 50V, 1.5A bipolar stepper motor driver with integrated current sensing and stall detection.

The main component BOM is listed in the table below:

Summary

Through the disassembly of the Xiaomi YU7 front headlight driver board, we can clearly see the current status and trends of China's new energy vehicle supply chain. Xiaomi did not sacrifice product performance in pursuit of marketing gimmicks like "full self-research" or "all-domestic." In areas involving functional safety cores and high algorithm complexity, such as MCUs and dedicated driver ICs, they firmly continued to use top-tier international solutions from Renesas, Infineon, and TI, ensuring the reliability baseline for the YU7 as a high-end model. However, in the field of power devices where technology is relatively mature and process requirements are slightly lower, Yangjie Technology's MOSFETs have proven that they are not only usable but also effective and cost-efficient, indicating huge potential for future substitution. True localization is not an overnight "de-Americanization," but rather a gradual increase in the proportion of autonomous controllability while guaranteeing an extreme user experience.