ニュース
Automotive wireless phone charging reference design
It combines Rohm’s automotive-grade wireless power transmission control IC (AEC-Q100 qualified BD57121MUF-M) with two STMicroelectronics’ chips, and NFC reader (ST25R3914) and an 8bit microcontroller (STM8A).
NFC communication is included for authentication, to allow Bluetooth or WiFi communication with vehicle’s infotainment system, lock and unlock 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,” said Rohm.
Rohm-automotive-Qi-BD57121MUF
Due to the use of NFC, foreign object detection has been enhanced over standard Qi.
“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,” said Rohm. “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.”
By automatic antenna tuning, the ST NFC chip can also adapt to keys, coins or other metallic objects near its antenna.
Phone charging and simultaneous NFC pairing for Bluetooth or Wi-Fi is supported.
Three coils are included to provide some spatial freedom in phone position without loosing coupling.
“At present, Qi has already been adopted by the European Automotive Standards Group [CE4A] as the charging standard in vehicles,” said Rohm.
The reference design was exhibited at the International Car Electronics Technology Show in Tokyo, and an evaluation board designed around it (BD57121MUF-M, pictured) will be available in April, to work with the firm’s existing Qi certified receiver board (BD57015GWL-EVK-002).
NFC communication is included for authentication, to allow Bluetooth or WiFi communication with vehicle’s infotainment system, lock and unlock 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,” said Rohm.
Rohm-automotive-Qi-BD57121MUF
Due to the use of NFC, foreign object detection has been enhanced over standard Qi.
“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,” said Rohm. “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.”
By automatic antenna tuning, the ST NFC chip can also adapt to keys, coins or other metallic objects near its antenna.
Phone charging and simultaneous NFC pairing for Bluetooth or Wi-Fi is supported.
Three coils are included to provide some spatial freedom in phone position without loosing coupling.
“At present, Qi has already been adopted by the European Automotive Standards Group [CE4A] as the charging standard in vehicles,” said Rohm.
The reference design was exhibited at the International Car Electronics Technology Show in Tokyo, and an evaluation board designed around it (BD57121MUF-M, pictured) will be available in April, to work with the firm’s existing Qi certified receiver board (BD57015GWL-EVK-002).