Wireless power supplies are becoming increasingly common in smartphones, smartwatches, and other compact devices. By using wireless power technology, devices can improve water and dust resistance by eliminating the need for terminal contacts. However, existing low-frequency standards for power transmission—along with restrictive antenna designs—limit the degree of miniaturization that can be achieved. These limiting factors are accelerating the demand for standards and methods that can be universally adopted in compact devices. Furthermore, power transmission efficiency can vary depending on the antenna's shape, size, and distance. Therefore, repeated prototyping, tuning, and evaluation are often required, representing a significant development burden for antenna design and layout.
In response to this situation, ROHM has developed 13.56 MHz wireless charging modules that allow users to easily add wireless power functionality to thin and compact devices. Measuring only 20 mm² to 30 mm² each, the BP3621 (transmitter) and BP3622 (receiver) feature an optimized antenna (coil) arrangement, enabling the configuration of a compact wireless charging system that utilizes the 13.56 MHz frequency band to deliver up to 200 mW. The completely flat backplate design facilitates mounting in thin and compact devices, contributing to greater chassis design flexibility compared to conventional solutions. Furthermore, using the transmitter and receiver modules as a pair can significantly reduce the development burden for prototyping, tuning, evaluation, and other processes required to achieve high-efficiency wireless charging. At the same time, the integrated antenna supports bidirectional data communication and NFC Forum Type 3 tag operation, thus expanding its applicability.
In the future, ROHM will continue to develop compact modules with efficient power transfer of up to 1W and also NFC Forum compatible to support a wider range of applications.
Product range
Availability
Available for purchase through online distributors Digi-Key, Mouser and Farnell.
Support Information
The following materials necessary to achieve wireless functionality are already available on the ROHM website:
• Data sheets
• Application notes
Application examples
• Compact devices such as smart tags, smart cards and ID cards
• Mice, remote controls and other PC peripherals
• Portable healthcare equipment
