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.
|DB3108: High performance HF reader / NFC initiator with 1 W supporting VHBR and AAT||1.0||117 KB|
|AN4974: Antenna matching for ST25R3911B/ST25R391x devices||2.0||3 MB|
|AN4914: Automatic Antenna Tuning (AAT) of ST25R3911B/ST25R391x devices||2.0||1 MB|
|AN5043: Layout recommendations for the design of boards with ST25R3911B/ST25R391x devices||4.0||873 KB|
|ST25R series overview||1.0||3 MB|
|High performance NFC/RFID readers||1.0||981 KB|
|NFC solutions from ST||1.0||3 MB|
|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||NRND : Not Recommended for New Design. Product is in volume production only to support customers ongoing production.||-||-||NEC||EAR99||-||MORE INFO||DISTRIBUTOR AVAILABILITY|
|Part Number||Marketing Status||Package||Grade||RoHS Compliance Grade||Material Declaration**|
|ST25R3911-BQFT||NRND||VFQFPN 5X5 32L PAD 3.5X3 PUNCHED||Industrial||N/A|
(**) 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.