New System-in-Package Brings NFC Payment to Wearables

STMicroelectronics has released its ST53G system-in-package (SiP). The solution consists of an integrated secure element (SE) and RF booster, in the same package, that can be built into wearable devices such as watches, fitness trackers, electronic handsets or toys, to make contactless payments secure. The SE is part of the company's ST31 family of 32-bit secure microcontroller units, using Near Field Communication NFC.

Already, electronic devices such as smart watches, smartphones and tablets are being equipped with NFC-enabled technology that can act as NFC readers and tags. However, says Christian Vignes, STMicroelectronics' banking and ID marketing director, only a small percentage of the several billion watches manufactured annually are smart watches. The others may have the capacity to benefit from NFC payment technology, however, by embedding similar technology in a credit card.

The ST53G enables contactless payments or other NFC functionalities to be integrated into battery-powered watches.

The ST53G is designed to enable NFC card emulation capability in wearables for single or dual contactless applications, the company reports. The module consists of ST's ST31G480 dual interface SE, which is compliant with the ISO 14443 standard, as well as a booster, to bring the read range up to 10 centimeters (3.9 inches), depending on the antenna's application and size.

Typically, the antenna can be very small, says Christian Vignes, the central marketing director of banking and ID for STMicroelectronics' Secure MCU Division. The ST53G module, with the SE and booster, is delivered in a 4-millimeter (0.2-inch) square format. The booster enables the device to accomplish that 10-centimeter read range reliably, the company explains, despite the small antenna size. Traditional contactless or NFC-enabled tags and cards typically have an antenna that leverages the product's entire space. In the case of wearables, companies lack the luxury of that much space.