STMicroelectronics – Integrated reader IC offers built-in compliance with multiple NFC protocols



STMicroelectronics’ ST25R3911B is a highly integrated NFC reader IC, which includes an RF Analogue Front End (AFE) and a data framing engine compliant with various NFC and RFID protocols.

The ST25R3911B is intended for use in NFC infrastructure equipment in which the user needs high RF performance and flexibility combined with low power consumption.

This reader IC offers the built-in capability to perform various NFC functions, including:
• ISO 18092 (NFCIP-1) initiator
• ISO 18092 (NFCIP-1) active target
• ISO 14443A or ISO 14443B reader, supporting high bit rates
• ISO 15693 reader
• FeliCa™ reader

Implementation of other standard and custom protocols, such as MIFARE™ Classic, is possible using the ST25R3911B’s AFE, and implementing framing in an external microcontroller.

The device features automatic antenna tuning technology for use in applications with directly driven antennas. The ST25R3911B contains two differential low-impedance antenna drivers.

The ST25R3911B offers various features which conserve energy in power-constrained applications. It has a low-power capacitive sensor which provides a wake-up function, enabling the main NFC reader circuit to be held in quiescent mode until the capacitive sensor detects the presence of an NFC tag or card.

The ST25R3911B also contains a low-power Resistor/Capacitor (RC) oscillator and wake-up timer which can be used to wake-up the system after a set time period, and to detect the presence of a tag.

The ST25R3911B reader may be used with the ST range of NFC interface tag ICs: the ST25DV04K, ST25DV16K and ST25DV64K devices are NFC RFID tags featuring 4kbits, 16kbits or 64kbits of EEPROM memory. These tag ICs provide an I2C interface to a host microcontroller as well as a wireless interface to any NFC or RFID reader.


  • Dynamic Power Output function
  • User-selectable and automatic gain control
  • Capable of driving two antennas in single-ended mode
  • Oscillator input capable of operating with 13.56MHz or 27.12MHz crystal with fast start-up
  • Serial peripheral interface
  • Supply-voltage range: 2.4V to 5.5V
  • Operating-temperature range: -40°C to 125°C


  • NFC infrastructure equipment


The ST25R3911B-DISCO is a ready-to-use kit featuring the ST25R3911B HF reader/NFC initiator IC.

The ST25R3911B-DISCO can be operated as ISO18092 (NFCIP-1) active and passive initiator, ISO18092 (NFCIP-1) active target, ISO 14443A and B reader supporting very high bit rates, or a long-range ISO15693 and FeliCa™ reader.

Orderable Part Number: ST25R3911B-DISCO