r/ECE • u/ChinaChipChat_ • 1d ago
PROJECT Teardown of a Tesla Model 3 headlight controller. Extreme TI density, glued closure, and literally a lobster silkscreen on the PCB.
Torn open a headlight driver module from a Tesla Model 3. Uploaded a short video clip showing the teardown process and close-ups of the board layout.
Unlike the headlight boards I looked at from Xiaomi or Aito, this one has zero screws. The whole unit is glued shut with heavy sealant, so getting it open took a pretty brutal prying process.
Inside, the thermal and spatial engineering is impressive. The thermal grease feeds heat directly from the power silicon straight into the aluminum fin enclosure. But the strangest detail is on the PCB itself: they actually printed custom artwork of a lobster and a cat right on the silkscreen next to the traces.
Hardware-wise, Tesla is clearly deeply in love with Texas Instruments. Outside of a few Onsemi MOSFETs and an NXP MCU, the board is basically a TI showcase:
Power and LED driving use three TI TPS92520-Q1 dual-channel buck LED drivers. Voltage regulation is handled by TI TPS7B8150 LDOs, along with a TI SN74LV4051A multiplexer.
On the communication side, they run both CAN (TI TCAN1042) and LIN (TI LIN1029) transceivers. Most other EV headlight modules I have pulled apart skip the LIN transceiver entirely.
They also packed in two TI DRV8889-Q1 stepper motor drivers. That points straight to an active adaptive front-lighting system (AFS) for driving lens stepper motors on cornering, which explains the tighter layout.
Main control is handled by an old-school NXP/Freescale S9KEAZN64 (Cortex-M0+) MCU, and Onsemi takes care of the rest with NVTFS6H880N and NTTFS6H860 N-channel FETs plus an NCV78702 LED driver.
There are still a couple of unconfirmed components. Two chips on the board are marked 100V L08E (looks like discrete components based on the package and layout) and an ST chip silkscreened VN114T, which is likely a high or low-side driver.
The layout density here is textbook tier. Putting Easter egg silkscreens on a tight automotive safety board shows just how confident their hardware team was with space management.