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The ST25R3911B is a highly integrated NFC Initiator / HF Reader 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), ISO 15693 reader 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 ST25R3911B 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 (AAT) technology, the device is optimized for applications with directly driven antennas. The ST25R3911B is alone in the domain of HF reader ICs as it contains two differential low impedance (1 Ohm) antenna drivers.
The ST25R3911B 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 ST25R3911B 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, ISO15693 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 demodulator channels with automatic selection
- DPO (Dynamic power output)
- Up to 1.4 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
Sample & Buy
| Part Number | Package | Packing Type | Marketing Status | ECCN (US) | Country of Origin | Approximate Price (US$)* / Qty | Order from ST | Order from Distributors |
|---|---|---|---|---|---|---|---|---|
| ST25R3911B-AQFT | VFQFPN 5X5 32L PAD 3.5X3 PUNCHED | Tape And Reel | Active | EAR99 | TAIWAN | 2.8 / 1k | Get sample | Check Availability |
| ST25R3911B-AQWT | VFQFPN 5X5X1 32L WETTABLE FLANKS | Tape And Reel | Active | EAR99 | - | 2.8 / 1k | No availability of distributors reported, please contact our sales office | |
| ST25R3911B-ASWB | US WF V.I. | Not Applicable | Active | EAR99 | - | 4.92 / 1k | No availability of distributors reported, please contact our sales office |
ST25R3911B-AQWT
Package
VFQFPN 5X5X1 32L WETTABLE FLANKSPacking Type
Tape And ReelApproximate Price (US$)* / Qty
2.8 / 1kST25R3911B-ASWB
Package
US WF V.I.Packing Type
Not ApplicableApproximate Price (US$)* / Qty
4.92 / 1k(*) 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
Featured Videos
Ecosystems
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Picture Part number Manufacturer Description 
X-NUCLEO-NFC05A1 ST NFC card reader expansion board based on ST25R3911B for STM32 and STM8 Nucleos Part NumberNFC card reader expansion board based on ST25R3911B for STM32 and STM8 Nucleos
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Embedded Software
Evaluation Tools
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Picture Part number Manufacturer Description 
ST25R3911B-DISCO ST Discovery kit for ST25R3911B high performance HF reader / NFC initiator with 1.4 W output power, VHBR and AAT 
ST25R3911B-EMVCO -- EMVCo reference design for the ST25R3911B high performance HF reader Part NumberDiscovery kit for ST25R3911B high performance HF reader / NFC initiator with 1.4 W output power, VHBR and AAT
EMVCo reference design for the ST25R3911B high performance HF reader
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| Part Number | Marketing Status | Package | Grade | RoHS Compliance Grade | Material Declaration** |
|---|---|---|---|---|---|
| ST25R3911B-AQFT | Active | VFQFPN 5X5 32L PAD 3.5X3 PUNCHED | Industrial | Ecopack2 | |
| ST25R3911B-AQWT | Active | VFQFPN 5X5X1 32L WETTABLE FLANKS | Industrial | Ecopack2 | |
| ST25R3911B-ASWB | Active | US WF V.I. | 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.
