The launch of the new ROHM wireless power supply IC chipset marks a massive technological leap for the rapidly expanding wearable electronics market. ROHM has officially announced the development of a highly advanced, Near Field Communication (NFC) compatible power solution, consisting of the ML7670 receiver and the ML7671 transmitter.
For hardware engineers, product designers, and B2B professionals reading AarokaTech.com, this announcement directly addresses one of the most frustrating bottlenecks in modern device design: delivering reliable power to ultra-compact form factors like smart rings, smart bands, and peripheral smart pens. By leveraging the high-frequency 13.56MHz NFC band, this chipset is poised to become the new industry standard for miniaturized power transfer.
The Wearable Charging Dilemma: Why Qi Falls Short
The global smart ring market has experienced explosive growth over the past few years, driven primarily by advanced healthcare diagnostics and proactive fitness tracking applications. However, designing for the human finger introduces severe physical constraints.
For extremely small, ring-shaped devices, traditional wired charging ports are completely impractical, compromising both aesthetics and water-resistance ratings. Conversely, the conventional Qi wireless charging standard—developed by the Wireless Power Consortium and ubiquitous in modern smartphones—is incredibly difficult to implement in rings due to the massive physical constraints surrounding magnetic coil size.
This hardware limitation has driven an urgent, industry-wide demand for a proximity-based power transfer method capable of reliably charging ultra-compact devices without demanding excessive internal real estate. In response, NFC-based charging has attracted massive attention because its high-frequency operation enables drastic antenna miniaturization. Following the successful commercialization of their 1W ML7660/ML7661 chips, the newly optimized ROHM wireless power supply IC chipset targets an even smaller footprint.
Deep Dive: ML7670 Receiver and ML7671 Transmitter
Building upon a proven architectural foundation, the ML7670 and ML7671 are meticulously engineered for the unique demands of wearable tech. The maximum power transfer for this specific chipset is specified at a highly efficient 250mW.
Crucially, peripheral components—such as the complex switching MOSFETs typically required to supply power to the charging IC—are completely built-in. This high level of integration results in a turnkey solution that optimizes both the physical mounting area on the PCB and the overarching power transfer efficiency.
The ML7670 power receiver IC is a marvel of modern semiconductor engineering. It achieves an astonishing maximum power transfer efficiency of 45% within the 250mW low-output range. More impressively, it packages this capability into an industry-leading form factor measuring just 2.28 × 2.56 × 0.48mm. By optimizing critical internal elements—such as coil matching, advanced rectifier circuitry, and actively reducing losses in switching devices—ROHM has created a product that drastically surpasses the efficiency of comparable hardware in its class.
MCU-Free Operation and NFC Compliance
One of the most attractive features for OEMs and hardware developers is the chipset’s embedded intelligence. All of the complex firmware required for stable wireless power delivery is embedded directly within the IC itself. This completely eliminates the need for an external host Microcontroller Unit (MCU) just to manage the charging handshake. This innovation significantly reduces total board space, lowers the Bill of Materials (BOM) cost, and drastically slashes the development workload during the initial device design phase.
Furthermore, the chipset guarantees strict compliance with the NFC Forum (WLC 2.0) standard. This ensures seamless power transfer while maintaining backward compatibility with existing NFC-enabled devices, firmly positioning the ROHM chipset as a core foundational element in the rapidly expanding NFC wireless power ecosystem.
Case Study: Adoption by the SOXAI RING 2
This cutting-edge silicon is not just a theoretical prototype; it is already in full mass production and actively powering next-generation consumer devices. The chipset has been officially adopted in the SOXAI RING 2, which launched to the Japanese market in December 2025.
Developed by SOXAI, Inc., the SOXAI RING is Japan’s premier smart ring dedicated to clinical-grade sleep management. The device incorporates a massive array of sensors into a tiny band, including an optical vital sensor, temperature sensor, accelerometer, and Bluetooth Low Energy (BLE) communication module. The SOXAI RING 2 also features “Deep Sensing,” a proprietary photoplethysmography (PPG) sensor that relies on the reliable power delivery of the ROHM wireless power supply IC to continuously monitor physical health changes with unprecedented depth and precision.
Future Outlook and Applications
As IoT technology continues to shrink, the applications for this chipset are practically limitless. Beyond smart rings and bands, ROHM envisions this technology powering smart pens, advanced wireless earphones, and a vast array of other compact industrial and consumer wearables.
Going forward, ROHM has committed to continuing its aggressive promotion of device development that leverages extreme miniaturization and low-power consumption technologies. To facilitate immediate integration for hardware teams globally, ROHM is currently offering comprehensive evaluation boards and detailed reference designs through their official sales network.
