The ST21NFCL is a contactless front-end (CLF) based on Arm^® core and designed for integration in mobile devices and NFC-compliant products.

The ST21NFCL performs near-field communication (NFC) functions in the three operating modes: card emulation, reader/writer and peer-to-peer communication. It is based on an advanced Arm^® Cortex^®-M3 32-bit microcontroller. The ST21NFCL is designed to increase RF communication distances, ease NFC technology integration, and operate in efficient low power modes.

The ST21NFCL is best in class in terms of RF output power, working up to 2 W. Maximum power can be safely used to communicate thanks to a dynamic control: when a card is close, power is automatically reduced to ensure interoperability and standard compliance. To go with this outstanding output power, demodulation sensitivity is improved to maximize the communication distance with all types of cards.

The ST21NFCL card emulation mode does not require any external oscillator nor reference clock source. Thanks to active load modulation and automatic adjustments based on field strength, communication distance is maximized, and interoperability is ensured.

The ST21NFCL can operate in a very low power modes while detecting, thanks to an improved field detection sensitivity and a stable and efficient low power card detection mechanism, the presence of a reader, a card, or a tag beyond its rated communication distance.

The ST21NFCL exchanges data with the device application processor over the NCI 2.1 logical interface on top of the I²C connection. It features three external SWP master interfaces.

The ST21NFCL is manufactured in ECOPACK-compliant packages:

3.475 × 3.667 x 0.511 mm, 90-ball wafer-level chip-scale package (WLCSP), 0.35 mm pitch

2.559 x 2.581 x 0.455 mm, 49-ball wafer-level chip-scale package (WLCSP), 0.35 mm pitch.

To meet environmental requirements, ST offers the ST21NFCL devices in ECOPACK packages. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ECOPACK is an ST trademark.