ST25R3911B NFC / HF RFID Reader IC

Description

The ST25R3911B is a highly integrated NFC initiator/high frequency reader IC that includes an analog front end (AFE) and a highly integrated data framing system for ISO 18092 (NFCIP-1) initiators, ISO 18092 (NFCIP-1) active targets, ISO 14443A and B readers (including high bit rates), and FeliCa™ readers. Other standard and custom protocols such as MIFARE™ Classic can be implemented using AFE and framing (streaming and transparent mode) in an external microcontroller.
The ST25R3911B is perfectly positioned for the infrastructure side of NFC systems, where users need optimal RF performance and flexibility as well as low power.
Thanks to the automatic antenna tuning (AAT) technology, the device is optimized for direct drive antenna applications. the ST25R3911B is unique in the field of high frequency reader ICs because it contains two differential low impedance (1 ohm) antenna drivers.
The ST25R3911B includes several features that make it well suited for low power applications. It contains a low power capacitive sensor that can be used to detect the presence of a card without opening the reader field. The presence of a card can also be detected by measuring the amplitude or phase of the signal on the antenna LC slot and comparing it to a stored reference value. It also contains a low-power RC oscillator and wake-up timer that can be used to wake up the system after a defined period of time and check the presence of the tag using one or more low-power detection techniques (capacitance, phase or amplitude).
The ST25R3911B is designed to operate over a wide (2.4 V to 5.5 V) power supply range; the peripheral interface IO pins support a 1.65 V to 5.5 V power supply range.

Features

- ISO 18092 (NFCIP-1) active P2P
- ISO14443A, ISO14443B and FeliCa™.
- VHBR support (3.4 Mbit/s PICC to PCD architecture, 6.8 Mbit/s AFE and PCD to PICC architecture)
- Capacitive sensing - wake-up
- Automatic antenna tuning system provides tuning of antenna LC slots
- Automatic modulation index adjustment
- AM and PM (I/Q) demodulator channels with automatic selection
- DPO (Dynamic Power Output)
- Up to 1.4W at differential output - user selectable and automatic gain control
- Transparent and streaming modes for MIFARE™ Classic compatibility or other custom protocols
- Possibility to drive two antennas in single-ended mode
- Oscillator input capable of working with 13.56 MHz or 27.12 MHz crystals with fast start-up
- 6 Mbit/s SPI with 96 bytes FIFO
- Wide supply voltage range: 2.4 V to 5.5 V
- Wide temperature range: -40 °C to 125 °C
- QFN32, 5 mm x 5 mm package