NFC Wireless Power Transfer Experiment: ROHM's ML7670/ML7671 Evaluation Boards in Action

This video explores whether NFC (Near Field Communication), known mainly for data exchange at 13.56 MHz, can serve as a practical power source. Using ROHM's NFC wireless charging ICs (ML7671 transmitter / ML7670 receiver), the presenter measures real power delivery inside a radio anechoic chamber and builds a working smart band powered entirely without a battery.

■ NFC Power Transfer Fundamentals
- Electromagnetic induction explained with coil and magnet demonstrations
- Qi charging vs NFC charging: frequency, power level, coil size, and data capability

■ ROHM NFC Wireless Charging ICs
- ML7671 (transmitter) and ML7670 (receiver) evaluation boards, PCB-patterned coils, antenna design and matching support
- Commercial example: SOXAI RING 2 smart ring using the same ICs
- Measured power delivery: stable 150–200 mW, peaking around 250 mW under ideal conditions

■ Smart Band Demo & Data Communication
- Smart band running microcontroller, accelerometer, and display on wireless power alone
- Battery-integrated operation, mirroring accelerometer data to a receiver display via NFC
- Simultaneous power + data considerations, ML7661/ML7660 alternatives, and NFC tag functionality

If you are an electronics engineer, embedded developer, or hobbyist interested in wirelessly powering small wearables, this hands-on experiment shows what NFC wireless charging can realistically deliver today and which components and constraints to consider. Watch it to understand the trade-offs between Qi and NFC and how to evaluate these ICs for your own designs.