STMicroelectronics has introduced a miniaturized wireless battery-charging chipset designed to simplify and accelerate time-to-market for ultra-compact sports wearables, wellness monitors, medical sensors and remote controllers.
ST combined its STWBC-WA charging-transmitter controller and its STWLC04 wireless battery-charger receiver to create a chipset that transfers up to 1W of power with smaller coils than competing chipsets, the company says. The chipset features 11 mm-diameter coils on the receiver side and 20 mm for the transmitter, allowing for the design of slim form factor devices. The chipset eliminates the need for a conventional charging connector and simplifies enclosure design and sealing by preventing contamination by dirt or moisture.
The chipset supports wireless charging for lithium-ion or lithium-polymer batteries with safety features, including foreign-object detection, active transmitter-presence detection and receiver thermal protection. The receiver supports direct battery charging and features a 32-bit microcontroller core, buck converter with synchronous rectification and integrated drivers.
The STWBC-WA transmitter controller is packaged as a VFQFPN32 and priced at $2.70 in 1,000-unit quantities. The STWLC04 receiver is $1.30. An evaluation kit can be purchased from distributors for $112.