Proving the Business Case for the Internet of Things

STM development kit charges IoT devices

Steve Rogerson
August 16, 2018

Swiss electronics company ST Microelectronics has developed a plug-and-play wireless battery-charger development kit that lets users build compact chargers up to 2.5W with a 20mm-diameter coil, for charging small IoT devices and wearables such as smart watches, sports gear or healthcare equipment.
Built around the STWBC-WA wireless charging-transmitter controller, the kit comprises a charging base unit containing a transmitter board with the 20mm coil already connected and ready to use.
Getting started involves using the PC-based STSW-STWBCGUI software to configure the STWBC-WA and monitor runtime information such as power delivered, bridge frequency, demodulation quality and protocol status. The kit includes a dongle for running the gui.
The supporting ecosystem includes certified reference boards, software and detailed documentation to help developers deliver small and performing chargers into fast-growing new markets for smart objects and wearables.
The controller chip contains integrated drivers and natively supports full-bridge or half-bridge topologies for powering the antenna. The half-bridge option allows charging up to 1W with a smaller-diameter coil for an even more compact form factor. The chip supports all standard wireless-charging features, including foreign object detection and active presence detection for safe charging, and uses digital feedback to adapt the transmitted power for efficiency at all load conditions.
Two firmware options give users the choice of a fast turnkey product or customising the application using APIs to access on-chip peripherals including an ADC, uart and GPIOs.
The Steval-ISB045V1 kit is available for $42. STWBC-WA transmitter controller ICs are in production, priced from $2.82 in VFQFPN32 package for orders of 1000 pieces.