STWBC  

The STWBC is the digital controller for wireless battery charger (WBC) transmitters (TX) from STMicroelectronics, offering the most flexible and efficient solution for controlling power transfer to a receiver (RX) in WBC-enabled applications such as phones, wearables, and other battery powered devices that use electromagnetic induction for recharging.

As a member of the Qi Wireless Power Consortium and the PMA (Power Matters Alliance), ST ensures full compatibility with these leading wireless charging protocols and holds certification for the Qi 1.1.2 A11 standard.

The STWBC performs all the functions for transmitter control: thanks to the internal 96 MHz clock and supporting both half-bridge and full bridge topologies, it is able to precisely control the amount of transmitted power to match the requirements of the receiving unit in terms of maximizing the efficiency of the power transfer.

The STWBC comes with firmware options to offer customers the ability to personalize their end product without the need of external microcontrollers:

A turnkey Qi 1.1.2 A11 certified solution, fully interoperable with Qi enabled mobile phones.

API (application programming interface) access to customize the underlying firmware, for example modifying the behavior of the LEDs or GPIOs in response to the receiver behavior and supporting I²C and UART communication within a network.

The STWBC Qi 1.1.2 A11 certified solution is available in the STMicroelectronics STEVAL-ISB027V1 reference design, intended for all Qi compatible receivers such as in Qi enabled mobile phones.

In the reference design the STWBC integrates the foreign object detection (FOD): the digital feedback between TX and RX units allows the detection of metal objects close to the receiver that could result in potential hazards, enabling the STWBC to stop power transmission when such objects are detected.

The reference design is offered together with a complete ecosystem to support customers in building their applications, including the Qi 1.1.2 A11 certified board (STEVAL-ISB027V1), API libraries and documentation to develop software customizations, as well as a comprehensive graphical user interface to monitor real-time performance and diagnostics.

Key Features

• Digital controller for wireless battery charger transmitter
• Multiple Qi certified and PMA standard compatible
• Support for up to 5 W applications
  • Mobile
  • Wearable, sports gear, medical
  • Remote controllers
• Native support to half-bridge and full bridge topologies
• 5 V supply voltage
• 2 firmware options
  • Turnkey solution for quick design
  • APIs available for application customization1
• Peripherals available via APIs
  • ADC with 10 bit precision and 1 MΩ input impedance
  • UART
  • I²C master fast/slow speed rate
  • GPIOs
• Memory
  • Flash and E²PROM with read-while-write (RWW) and error correction code (ECC)
  • Program memory: 32 KBytes Flash; data retention 15 years at 85 °C after 10 kcycles at 25 °C
  • Data memory: 1 KByte true data E²PROM; data retention:15 years at 85 °C after 100 kcycles at 85 °C
  • RAM: 6 KBytes
• Reference design features
  • 2 layers PCBs
  • Active object detection
  • Graphical user interface for application monitoring
  • Evaluation boards
• Operating temperature: -40 °C up to 105 °C
• Package: VFQFPN32