ROHM partners with STMicroelectronics to deliver automotive-grade wireless charging solution with NFC communication

28 January 2019

ROHM wireless charging solution with NFC communication image4

Combining the Qi standard with NFC communication enables innovative products in automotive applications.

ROHM recently announced the development of an automotive wireless charging solution with integrated NFC communication. This solution combines ROHM’s automotive-grade (AEC-Q100 qualified) wireless power transmission control IC (BD57121MUF-M) with STMicroelectronics' NFC Reader IC (ST25R3914) and 8-bit microcontroller (STM8A series). In addition to being compliant to WPC’s Qi standard, supporting EPP (Extend Power Profile), which enables the charger to supply up to 15W of power, the multi-coil design enables a wide charging area that provides some spatial freedom in vehicle applications (2.7x greater charging range versus single coil configurations). This means consumers do not need to worry about precisely aligning their smartphones to the charging area in order to be able to charge wirelessly.

Wireless charging technology, commonly used in portable devices such as smartphones to improve the safety and resistance to water and dust of connectors, is seeing increased adoption in infrastructure applications –including vehicles, hotels, airports, cafes and similar public locations. At present, Qi, the most popular standard, has already been adopted by the European Automotive Standards Group (CE4A) as the charging standard in vehicles – and by 2025, it is predicted that most cars will be equipped with Qi-based wireless chargers.

Meanwhile, NFC communication provides user authentication to allow Bluetooth/WiFi communication with infotainment system, lock/unlock the doors and allow engine start. NFC also enables vehicle setting customisation for multiple drivers, such as seat and mirror positioning, infotainment pre-sets and navigation destination pre-sets.

A reference board integrating this solution will be exhibited at the 11th International Car Electronics Technology Show at Tokyo Big Sight from January 16 to 19, 2019. In the future, ROHM plans on releasing a sample reference board that will allow users to easily configure a wireless charger for automotive use, compatible with the latest Qi standard (EPP), when combined with its Qi certified receiver board (BD57015GWL-EVK-002), already on the market.

ROHM is committed to develop solutions that will enable greater convenience and performance for the rapidly expanding wireless charging market.

Availability: February (the reference board), April (BD57121MUF-M)

Key Features:
1. Foreign object detection (detects NFC cards in smart cases)

Per the Qi standard, a foreign object detection function for detecting metallic objects is included to prevent deformation or damage from occurring due to excessive heat generation in the event a metallic object is placed between the transmitter and receiver. This time, however, designers were faced with the challenge of ensuring detection of the NFC antenna can damage the NFC card by the magnetic field. This was achieved by integrating an NFC communication function that enables detection of the NFC card even when inserted in a smartphone case or the like.

2. NFC enables seamless infotainment operation via device authentication
Previously, when connecting smartphones to infotainment systems it was necessary to perform manual pairing for each device. However, by combining Qi wireless charging with NFC communication, ROHM made it possible to not only charge mobile devices such as smartphones, but also perform Bluetooth or WiFi pairing at the same time through NFC authentication. To use, simply place a smartphone on the charging pad to automatically initiate screen sharing with the infotainment and navigation system.

3. Achieves system sharing via personal authentication using NFC
In the future, all vehicles are expected to utilise NFC protocol to connect smart devices with the onboard system to provide shared functionality that does not rely on traditional keys or dedicated cards.

ROHM wireless charging solution with NFC communication image1

ROHM wireless charging technology
As a regular member of WPC, ROHM actively participates in working groups, from the initial stages of specification development, for the increasingly popular Qi wireless power standard, and it has been quick to develop 15W-class control ICs and reference designs that meet market needs.

In 2016, ROHM began selling the industry’s first 15W class Qi certified transmission (BD57020MWV-EVK-001) and receiver (BD57015GWL-EVK-001) reference boards. These boards were released to promote the adoption of wireless charging solutions. This latest board, the BD57121MUF-M (transmission) is AEC-Q100 compliant to support automotive applications.

STMicroelectronics NFC Reader ICs
The ST25R3914/3915 automotive-grade NFC Reader ICs are compatible with ISO14443A/B, ISO15693, FeliCa and ISO18092 (NFCIP-1) Active P2P, they incorporate a high-performance analogue front end, featuring best-in-class receiver sensitivity that delivers reliable foreign-object detection performance in vehicle centre consoles.

The ST25R3914 includes ST’s proprietary Automatic Antenna Tuning function that adapts to surrounding environment changes in order to minimise the effects from metallic objects near the reader antenna, such as keys or coins placed on the center console. In addition, MISRA-C: 2012 compliant RF middleware is available to allow customers to reduce their software development effort.

STMicroelectronics Automotive 8-bit MCUs
The STM8A, high-performance automotive 8-bit MCU series is available in a variety of packages and memory sizes. Moreover, the pin-compatible lineup allows users to select the best product fits for required functions and performance. Devices with embedded data EEPROMs are also offered, including CAN-equipped models featuring an extended operating temperature range guaranteed up to 150°C, making them ideal for a variety of automotive applications.


NFC (Near Field Communication) is an established technology that facilitates the introduction of innovative applications by enabling wireless, contactless communication at 13.56MHz. NFC’s unique features are expected to make a significant impact in a variety of areas, including smart homes, industrial equipment and portable devices. STMicroelectronics, a leading provider of NFC technologies, offers a comprehensive portfolio that allows users to develop the most efficient and secure solutions for a variety of applications.

AEC-Q100 is a failure-mechanism-based stress test established by the Automotive Electronics Council, an organisation comprised of major automotive manufacturers and US electronic component makers responsible for establishing reliability standards for the automotive electronics sector.

WPC Qi Standard
WPC (Wireless Power Consortium) is a standards organisation established to formulate and promote the Qi international standard for wireless charging. WPC is currently the largest international standards organisation for wireless charging, with over 638 member companies as of November 2018.

CE4A (Consumer Electronics for Automotive) is an organisation promoting the standardisation of interfaces between portable devices (ie mobile phones, compact audio players, beacons) and automotive ECUs (Electronic Control Units).

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