Xiaomi SU7 Wireless Charging Module Teardown

As a phenomenon in the new energy vehicle sector, every detail of the Xiaomi SU7 has drawn significant attention. Previously, eefocus teardowns covered the SU7’s headlight driver board, onboard fast charging module, and T-BOX connected car module. This time, we are tearing down another representative component — the onboard wireless charging module. Unlike common aftermarket in-car wireless chargers, this front‑loaded module must meet much stricter automotive‑grade requirements.

Teardown

The disassembled components are shown in the figure below, including the enclosure, cooling fan, and PCB main board.

Let’s focus on the PCB main board. The main components include:

LDO from 3PEAK, model TPL730F33 — a 300mA output current, high PSRR low dropout linear regulator. The high PSRR characteristic ensures that digital switching noise does not interfere with the wireless charging signal detection.

DC/DC chip from MPS, model MP2459 — a 55V input, 480kHz switching frequency step‑down converter, providing auxiliary power to various low‑voltage modules within the system.

High‑power wireless charging IC from FuDa Semiconductor**, model NU8040Q — supports high‑power wireless charging protocols, integrating a full‑bridge driver and efficiency optimization algorithms.

High‑efficiency, synchronous buck‑boost controller from Southchip, model SC8701Q — converts the vehicle’s 12V/24V power to an intermediate voltage required for wireless charging. The buck‑boost topology maintains a stable output voltage even when the input voltage fluctuates, making it ideal for automotive electrical systems.

Bi‑directional TVS from Littelfuse, reverse stand‑off voltage 30V, model SMBJ30CA; and one SPI Flash with marking P4C08C1.

The other side of the PCB includes:

Wireless charging main controller from NXP, model FS32K144HFVLL — an automotive‑grade MCU based on the Arm Cortex‑M4F core. The M4F core includes a floating‑point unit, offering significant advantages when processing complex wireless charging algorithms (such as frequency tracking, power regulation, and foreign object detection).

CAN transceiver from Texas Instruments, model TCAN1043‑Q1 — an automotive CAN FD transceiver with flexible data‑rate and wake‑up input.

NFC reader IC from STMicroelectronics, model ST25R3920B — used for phone identification and charging protocol handshake. It reads the wireless charging authentication information from the phone, determining whether it supports Xiaomi’s proprietary fast charging protocol.

N‑MOSFET from Alpha & Omega Semiconductor, model AON7264E** — this MOSFET appears on both sides of the PCB and is used for power path control and load switching. Its low on‑resistance effectively reduces power loss.

The main component list is as follows:

Summary

The above describes the component selection and design of the first‑generation Xiaomi SU7 onboard wireless charging module, reflecting the growing maturity of China’s new energy vehicle supply chain. This is a wireless charging solution that balances charging speed and heat dissipation. The addition of an active cooling fan addresses the thermal rise pain point of high‑power wireless charging, while the NFC authentication mechanism ensures the security of the fast charging protocol.