NFC / HF RFID Reader IC

The ST25R3911 is a highly integrated HF reader / NFC initiator IC, including the analog front end (AFE) and a highly integrated data framing system for ISO 18092 (NFCIP-1) initiator, ISO 18092 (NFCIP-1) active target, ISO 14443A and B reader (including high bit rates) and FeliCa™ reader. Implementation of other standard and custom protocols like MIFARE™ Classic is possible using the AFE and implementing framing in the external microcontroller (Stream and Transparent modes).

The ST25R3911 is positioned perfectly for the infrastructure side of the NFC system, where users need optimal RF performance and flexibility combined with low power.

Thanks to Automatic Antenna Tuning technology the device is optimized for applications with directly driven antennas. The ST25R3911 is alone in the domain of HF reader ICs as it contains two differential low impedance (1 Ohm) antenna drivers.

The ST25R3911 includes several features that make it very suited for low power applications. It contains a low power capacitive sensor that can be used to detect the presence of a card without switching on the reader field. The presence of a card can also be detected by performing a measurement of amplitude or phase of signal on antenna LC tank, and comparing it to the stored reference. It also contains a low power RC oscillator and wake-up timer that can be used to wake up the system after a defined time period, and to check for the presence of a tag using one or more low power detection techniques (capacitive, phase or amplitude).

The ST25R3911 is designed to operate from a wide (2.4 V to 5.5 V) power supply range; peripheral interface IO pins support power supply range from 1.65 V to 5.5 V.

Key Features

  • ISO 18092 (NFCIP-1) Active P2P
  • ISO14443A, ISO14443B and FeliCa™
  • Supports VHBR (3.4 Mbit/s PICC to PCD framing, 6.8 Mbit/s AFE and PCD to PICC framing)
  • Capacitive sensing - Wake-up
  • Automatic antenna tuning system providing tuning of antenna LC tank
  • Automatic modulation index adjustment
  • AM and PM (I/Q) demodulator channels with automatic selection
  • Up to 1 W in case of differential output
  • User selectable and automatic gain control
  • Transparent and Stream modes to implement MIFARE™ Classic compliant or other custom protocols
  • Possibility of driving two antennas in single ended mode
  • Oscillator input capable of operating with 13.56 MHz or 27.12 MHz crystal with fast start-up
  • 6 Mbit/s SPI with 96 bytes FIFO
  • Wide supply voltage range from 2.4 V to 5.5 V
  • Wide temperature range: -40 °C to 125 °C
  • QFN32, 5 mm x 5 mm package

Resources

Technical Documentation

Product Specifications
Description Version Size
DB3108 DB3108: High performance HF reader / NFC initiator with 1 W supporting VHBR and AAT 1.0 117 KB

Presentations & Training Material

Presentations
Description Version Size
ST25R series overview 1.0 3 MB

Publications and Collaterals

Flyers
Description Version Size
High performance NFC/RFID readers 1.0 981 KB
Support & Community


Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
ST25R3911-BQFT VFQFPN 5X5 32L PAD 3.5X3 PUNCHED Tape And Reel Active - - NEC EAR99 - MORE INFO DISTRIBUTOR AVAILABILITY
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(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
ST25R3911-BQFT ActiveVFQFPN 5X5 32L PAD 3.5X3 PUNCHEDIndustrialN/A 0 0
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(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.

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