Application of Bluetooth Tire Pressure Monitoring -- Tesla TPMS Scheme

According to relevant information, Early Tesla TPMS supplier is China Shanghai Factory. Its early TPMS design scheme was implemented with traditional RF signals, and a receiver was specially used to receive the TPMS RF signals. As shown in the figure below, not only the four TPMS sensors are similar to the traditional TPMS, but also the receiving end. The TPMS ECU of Shanghai Factory is not integrated, but placed on it separately.

Shanghai Factory adopts a single-chip SOC solution based on Infineon SP40. From the perspective of traditional RF signals, the performance of Infineon SP series tire pressure sensors is also a good choice. But unfortunately, our employer is Tesla.

At the beginning of 2020, Tesla switched the Shanghai Factory TPMS sensor solution on its Model Y, and also switched the Model 3 products at the end of 2020.

From the perspective of the entire design evolution, Tesla concentrated the entire frequency band at 2.4Ghz, canceling the 315MHz and 433MHz of the original Tesla TPMS.

In terms of design direction, Tesla uses the Bluetooth solution to realize the TPMS function. It replaces traditional radio frequency products through system electrical Bluetooth TPMS. They started to try it in 2020, and just started using a Taiwanese company to exclusively supply the Model Y single model, and then introduced the Model 3 in October 2020. By mid-January 2021, Tesla has increased the order and switched all Tesla TPMS to the Bluetooth version.

Earlier versions used the M96403 tire pressure sensor and TI's CC2640 microcontroller. The TPMS sensor battery uses Murata and Maxell two vehicle-grade button batteries, and the MCU is TI's low-power CC2642 microcontroller.

From the latest information, Tesla has updated its TPMS solution. From the latest solution design, it feels that the Bluetooth part has been integrated into the MCU, and a dedicated Bluetooth SOC is used. This is equivalent to getting rid of the shackles of the original TPMS chip. In fact, the main advantage is that the MCU has more authority to do coding. Bluetooth technology has also gotten rid of the original 433MHZ and 315MHZ frequency band restrictions, and can get free receiver reception in used on 2.4GHZ.

Overall: As the tire pressure solution of Bluetooth technology, Tesla, as an industry pioneer, leads the direction of the industry. It is believed that in the near future, Bluetooth technology will gradually replace the traditional 433M RF signal transmission and become the mainstream.

According to relevant information, the Bluetooth tire pressure SOC with integrated air pressure chip has been mass-produced by relevant companies, and we expect more changes in the industry.