Wireless charging kit simplifies the development of chargers for wearables

By Warren Miller, contributing writer

STMicroelectronics recently unveiled the STEVAL-ISB045V1 wireless battery charger development kit for creating compact chargers for wearable and IoT devices. Included in the plug-and-play kit is everything you need — software, documentation, reference boards, and hardware — to construct and support small wireless chargers up to 2.5 W with a space-saving 20-mm diameter coil for charging small devices such as smartwatches, sports gear, and health care equipment.

The development kit is built on the STWBC-WA wireless charging transmitter controller, which is comprised of integrated drivers, to support full- and half-bridge topologies for powering the antenna. Half-bridge designs can use an even smaller diameter coil while charging up to 1 W for a smaller form factor. The chip can function as a turnkey solution or be customized for specific applications by using various APIs to access on-chip peripherals including an ADC, a UART, and GPIOs.

The STWBC-WA supports all common wireless charging features, including active presence detection for safe charging and foreign object detection. The chip also employs digital feedback to adjust power transmission levels to ensure optimal efficiency at all load conditions.

The kit includes a charging base unit that contains the transmitter board with the 20-mm coil, connected and ready to use, and a dongle for running the GUI. Designers can use the PC-based STWS-STWBCGUI software to configure the controller chip to monitor runtime operations like power delivery, protocol status, bridge frequency, and demodulation quality.

Wireless chargers for wearable and IoT devices capable of charging up to 2.5 W are easily developed with STMicroelectronics’ STEVAL-ISB045V1 wireless charging kit, which is currently available for $42. The STWBC-WA transmitter controller ICs are in production and priced from $2.82 per unit (VFQFPN32 package) for orders of 1,000 units. You can find out more about the kit and order it here.