ROHM, a semiconductor specialist, has introduced an NFC-based wireless charging IC chip set optimized for ultra-small wearable devices such as smart rings and smart bands, enabling stable wireless power supply even in small device environments.

Roum announced on the 12th that it has launched NFC-based wireless charging ICs, 'ML7670' for receiving and 'ML7671' for transmitting.

The new product is based on the existing 1W wireless charging solution, but the output power has been adjusted to 250mW to be suitable for ultra-small devices such as smart rings.

In particular, key circuits such as the switching MOSFET required for charging were integrated into the chip to reduce the number of external components, thereby minimizing mounting area and increasing power efficiency during device design.

The ML7670 receiving IC utilizes an ultra-small package measuring 2.28×2.56×0.48mm, increasing the design freedom of wearable devices.

It achieves a charging efficiency of up to 45% even in low-power ranges, securing performance competitiveness compared to products in the same class.

ROHM explained that it achieved efficiency improvements by optimizing coil matching, rectification circuits, and switching loss reduction technology.

Also wireless chargerBy embedding the necessary firmware inside the chip, system configuration is possible without a separate host MCU.

This contributes to the simplification of the development process and product miniaturization, and is considered a factor that reduces the development burden on wearable device manufacturers.

The chip set meets the NFC Forum's wireless charging standard (WLC 2.0), ensuring compatibility with existing NFC-based charging systems.

Accordingly, it is expected to be utilized as a key component in the expanding NFC wireless charging ecosystem in the future.

ROHM's new wireless charging chip has already entered the mass production stage and has been applied to the 'SOXAI RING 2', a smart ring for sleep management released by the Japanese company SOXAI.

This product is a wearable device that combines biosignal measurement, wireless communication, and NFC charging functions, and supports precise sleep data analysis.

ROHM plans to support customer product verification and development by also providing evaluation boards and reference designs.

The company plans to continue introducing semiconductor solutions that meet the demands of the wearable market based on small and low-power technologies.