STMicroelectronics ST25R3911B-AQFT RFID Reader, 13.56MHz, SPI, ISO 14443, NFC, 2.4V-5.5V, -40 to 125°C, 32-QFN (5x5).
| Parameter | Value |
|---|---|
| Type | RFID Reader |
| Series | ST25R |
| Mounting | Surface Mount |
| Voltage | 2.4V ~ 5.5V |
| Frequency | 13.56MHz |
| Interface | SPI |
| Operating temperature | -40°C ~ 125°C |
| Standards | ISO 14443, NFC |
| Package | Tape & Reel (TR) Cut Tape (CT) |
| Case | 32-VFQFN Exposed Pad |
ISO 14443 covers Type A and Type B contactless smartcards — the common infrastructure for transit ticketing and physical access. NFC support extends the reader to peer-to-peer and card-emulation modes, which is what mobile wallets and NFC tag commissioning tools rely on. If you only need to read legacy 125 kHz tags, this is not the part; for 13.56 MHz contactless, it covers the dominant standards.
ST lists the ST25R3911B-AQFT as Active.
The ST25R3911B is the current-production evolution of the ST25R3911A. It is pin-compatible and functionally equivalent for ISO 14443 and NFC applications. If you have a BOM with the A-variant, the B-variant is the recommended drop-in replacement for new builds.
The listed standards are ISO 14443 and NFC. ISO 14443 covers Type A and Type B cards. NFC support includes peer-to-peer and card-emulation modes, which typically covers Type 5 (ISO 15693) compatibility through the NFC framework, but confirm the exact tag type against your application note.
Yes, the supply range is 2.4V to 5.5V, so 3.3V is well within the operating window. No external regulator is needed if your MCU rail is 3.3V.
Lead time varies with market conditions and order quantity. We confirm lead time at quote against an RFQ — it is typically quoted in weeks, not months, for this active ST part.