AFE, SIP make NFC transactions a reality, even in wearables

The promise of near-field communication (NFC) has always been that it would make a lot of things easier, such as making payments, showing admittance tickets, gaining access electronically, and so on. Unfortunately, that hasn’t been the case; aligning the NFC device with a reader has not only been tricky and unreliable, it’s also required a serious commitment of physical space to implement the required antenna. But that changed this week at Mobile World Congress in Barcelona, where ams and STMicroelectronics demonstrated a new system that overcomes these drawbacks, and make NFC in small wearables practical.

Shown in the form of a reference design, the system combines the AS39230, a new analog front-end (AFE) from ams with boostedNFC technology, and STMicro’s ST21NFCC controller and ST33G1M2 Secure MCU. The combination provides what the companies claim is the fastest, safest, and most reliable secure contactless transactions in phones and wearables. Through the ST33G1M2 Secure Element, the technology also boasts worldwide certification, including for Common Criteria, EMVCo, GlobalPlatform, and Visa, MasterCard, Amex, and People’s Bank of China.

Key to the design’s performance is the AFE’s use of boostedNFC, a technology based on active load modulation (ALM). ALM increases the signal strength up to 10 times compared to conventional, passive load modulation (PLM) methods. Thus, in space-constrained designs, the size of the antenna can be reduced by as much as 20 times — down to 100 mm2 or less — while maintaining the same signal strength.

The ST21NFCC controller and the ST33G1M2 32-bit secure microcontroller are bundled into STMicro’s ST54E System-in-Package (SIP), which also contains embedded Secure Element and microSD-card applications. Together, the AS39230 and ST54E support all important NFC standards governing card emulation, including ISO14443 type A/B, FeliCa at data rates up to 424 kb/s, active peer-to-peer bit rates of 212 kb/s, and ISO18092 communication at up to 424 kb/s.

The AS39230 NFC analog front end is available in production volumes now ams, and the ST54E is available for sampling. An evaluation board, reference designs, pricing, and datasheets are available on request from the appropriate supplier.