ROHM Launches an Ultra-Compact Wireless Power Chipset for Wearables

ROHM has developed a wireless power supply IC chipset consisting of the receiver - ML7670 - and transmitter - ML7671 - compatible with Near Field Communication (NFC) technology for compact wearables such as smart rings and smart bands as well as peripheral devices like smart pens.

The smart ring market has seen rapid growth in recent years, primarily in healthcare and fitness applications. However, for extremely small ring-shaped devices worn on the finger, wired charging is impractical, while conventional Qi wireless charging standard is difficult to implement due to constraints such as coil size. This has driven increased demand for a proximity-based power transfer method capable of reliably charging ultra-compact devices.

In response, NFC-based charging, which operates at the high-frequency 13.56MHz band that enables antenna miniaturization, is attracting increased attention, with adoption accelerating in next-generation wearables. Following the successful commercialization of the 1W ML7660/ML7661, ROHM has developed the ML7670/ML7671 chipset optimized for even smaller devices.

This new chipset builds on the proven receiver - ML7660 - and transmitter - ML7661. The maximum power transfer is specified at 250mW, while peripheral components such as the switching MOSFETs required to supply power to the charging IC are built in. The result is a solution optimized for both mounting area and power transfer efficiency in the power class demanded by compact wearable devices, especially smart rings (more info).

robenek@dps-az.cz