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STMicroelectronics ST25R3915-AQFT
- Part No.:
- ST25R3915-AQFT
- Manufacturer:
- STMicroelectronics
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ST25R3915-AQFT.pdf
- Description:
- IC RFID READER 13.56MHZ 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,930
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Product details
Overview
ST25R3915-AQFT from STMicroelectronics is an AEC-Q100 Grade 1 qualified automotive HF NFC initiator/reader IC supporting ISO 14443A/B, ISO 15693, FeliCa™, and ISO 18092 (NFCIP-1) active P2P at up to 848 kbit/s, with 1 W differential RF output power, capacitive wake-up sensing, and 2.4–5.5 V supply range. It serves as the analog front-end and framing engine in automotive keyless entry, secure access, and vehicle-to-tag communication systems.
For engineers reviewing the ST25R3915-AQFT datasheet, ST25R3915-AQFT pinout, ST25R3915-AQFT application, or ST25R3915-AQFT equivalent, key selection considerations include AAT support (ST25R3914 only), differential antenna driver impedance (1 Ω), SPI interface speed (6 Mbit/s), operating temperature (−40 °C to +125 °C), and capacitive presence detection capability.
Technical Context
The ST25R3915 integrates dual 1 Ω differential antenna drivers enabling high-efficiency 1 W RF output without external matching networks. Its AM/PM (I/Q) demodulator supports automatic channel selection for robust signal recovery across ISO 14443, ISO 15693, and FeliCa™ protocols.
It implements low-power card presence detection via capacitive sensing, antenna LC tank phase/amplitude measurement, and a dedicated RC oscillator with wake-up timer - all operating independently of the main RF field. Stream and Transparent modes offload framing to an external MCU for MIFARE™ Classic or custom protocol implementation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| RF Output Power | Up to 1 W differential output enables extended read range (>10 cm) with standard 13.56 MHz antennas in automotive environments. |
| Data Rate Support | Up to 848 kbit/s HBR for both PICC→PCD and PCD→PICC framing per ISO 18092, enabling fast NFC handshaking. |
| Supply Voltage Range | 2.4 V to 5.5 V operation allows direct integration with automotive 3.3 V or 5 V domains without LDO overhead. |
| Operating Temperature | −40 °C to +125 °C ambient rating meets AEC-Q100 Grade 1 requirements for under-hood and cabin-mounted modules. |
| SPI Interface | 6 Mbit/s with 96-byte FIFO reduces host MCU intervention and supports real-time tag response handling. |
| Detection Methods | Capacitive sensing + LC tank phase/amplitude measurement enable <10 µA wake-up current for battery-backed systems. |
Pinout & Package
ST25R3915-AQFT is housed in a QFN32 package (5 mm × 5 mm, 0.5 mm pitch) with wettable flanks for automated optical inspection. The package supports thermal dissipation required for sustained 1 W RF output in automotive enclosures.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Main power supply input | Accepts 2.4–5.5 V; powers analog and digital blocks; requires local 100 nF + 10 µF decoupling. |
| ANT1P / ANT1N | Differential antenna port 1 | 1 Ω low-impedance differential output pair; supports 1 W RF drive into 50 Ω balanced load. |
| ANT2P / ANT2N | Differential antenna port 2 | Second independent 1 Ω differential driver; enables dual-antenna spatial diversity or redundancy. |
| CSN | SPI chip select | Active-low signal enabling multi-device SPI bus sharing; supports daisy-chain configuration. |
| IRQ | Interrupt request output | Open-drain signal indicating tag detection, framing completion, or error condition to host MCU. |
| WAKE | Capacitive sensor input | High-impedance node for external PCB pad; detects proximity via capacitance change without RF field activation. |
Key Features
| Feature | Design Value |
|---|---|
| Dual 1 Ω differential antenna drivers | Enables simultaneous or redundant 1 W RF output on two antennas without external power amplifiers or matching circuits. |
| Capacitive wake-up sensing | Reduces system standby current to <10 µA by detecting card proximity before enabling full RF field. |
| Automatic modulation index adjustment | Maintains optimal signal integrity across varying antenna loads and temperature drift without host calibration. |
| AM/PM (I/Q) demodulator with auto-selection | Improves decoding reliability in noisy automotive environments by dynamically choosing the higher-SNR channel. |
| Stream and Transparent framing modes | Offloads ISO 14443/MIFARE™ Classic protocol handling to external MCU while retaining full AFE control. |
Applications
| Automotive Keyless Entry | Secure Vehicle Access Control |
|---|---|
Use Scenario: Passive entry push-button start (PEPS) system where driver's NFC-enabled fob is detected within door handle. IC Role / Device Role / Timing Role: HF reader IC acting as initiator to poll and authenticate fob via ISO 14443A at 106–848 kbit/s. Use Value: 1 W RF output ensures reliable detection through metal-rich door structures; capacitive wake-up minimizes fob battery drain during idle. | Use Scenario: In-cabin biometric/NFC token authentication for vehicle personalization and encrypted data access. IC Role / Device Role / Timing Role: NFC initiator performing secure ISO 18092 active P2P handshaking with trusted mobile device or wearable. Use Value: Dual antenna ports allow spatial diversity to mitigate multipath nulls inside cabin; −40 °C to +125 °C rating ensures operation across climate zones. |
| Automotive Service Tag Reading | OBD-II Diagnostic Token Interface |
Use Scenario: Technician scans NFC service tag embedded in vehicle chassis to retrieve calibration data or recall status. IC Role / Device Role / Timing Role: ISO 15693 reader interrogating high-memory tags at 26.48 kbit/s with extended field stability. Use Value: Automatic antenna tuning compensation (via host-controlled algorithm) maintains coupling efficiency despite mechanical vibration or thermal expansion. | Use Scenario: Aftermarket OBD-II adapter uses NFC to exchange firmware updates or diagnostic logs with technician tablet. IC Role / Device Role / Timing Role: FeliCa™ and ISO 14443B reader supporting fast 848 kbit/s data transfer for encrypted log uploads. Use Value: 6 Mbit/s SPI with 96-byte FIFO prevents data loss during burst transfers; wide 2.4–5.5 V supply accommodates variable OBD-II rail voltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar HF NFC initiator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST25R3914-AQFT | Includes integrated automatic antenna tuning (AAT); same QFN32 package but VFQFPN32 variant with wettable flanks. | Preferred where antenna impedance drift due to temperature or mechanical stress must be compensated autonomously. | Select ST25R3914 if AAT is required; ST25R3915 offers identical RF performance without AAT circuitry, reducing BOM count. |
| NXP PN7150B | Lower max RF output (0.5 W); single antenna driver; no capacitive wake-up; supports NFC Forum-certified stack only. | Limited to consumer-grade NFC accessories; lacks AEC-Q100 qualification and extended temperature range. | Choose PN7150B only for non-automotive, cost-sensitive designs requiring certified NFC controller stack, not high-power or ruggedized operation. |
Compared with ST25R3914-AQFT, ST25R3915-AQFT removes AAT hardware for simplified layout and lower quiescent current, while retaining identical RF power, dual-antenna capability, and automotive qualification - making it optimal for fixed-tuned antenna systems. Versus PN7150B, it delivers double RF power, true automotive robustness, and flexible protocol framing beyond NFC Forum scope.
Availability
ST25R3915-AQFT is available at Aetrix Electronics and suitable for automotive keyless entry, secure vehicle access control, and OBD-II diagnostic token interfaces requiring stable component supply across extended temperature and lifecycle demands.
Supply support for ST25R3915-AQFT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader designing and manufacturing microcontrollers, power management ICs, sensors, and analog chips for automotive, industrial, and consumer markets.
The ST25R series targets automotive NFC infrastructure applications, delivering high-power, AEC-Q100-qualified HF readers with low-power wake-up and dual-antenna flexibility for secure, robust short-range wireless interaction.
FAQ
Does ST25R3915-AQFT support ISO 14443A card emulation mode?
No. ST25R3915-AQFT operates exclusively as an initiator/reader (PCD), not as a card emulator (PICC). It supports ISO 14443A/B, ISO 15693, FeliCa™, and ISO 18092 active P2P initiator modes. Card emulation requires a separate secure element or NFC controller with target-mode capability.
What is the function of the WAKE pin, and how is it implemented?
The WAKE pin is a high-impedance capacitive sensor input used for proximity detection without activating the RF field. It connects to a dedicated PCB pad; internal circuitry measures capacitance change caused by nearby objects. Detection triggers IRQ assertion, waking the host MCU to initiate full RF polling only when needed.
Can ST25R3915-AQFT drive a single-ended antenna?
Yes. While optimized for differential 50 Ω antennas, ST25R3915-AQFT supports single-ended antenna configurations using one differential pair (e.g., ANT1P to antenna, ANT1N grounded) with appropriate DC blocking and matching. ST provides reference layouts and impedance-matching guidelines in AN4915 for such implementations.
Is automatic antenna tuning (AAT) available on ST25R3915-AQFT?
No. Automatic antenna tuning is exclusive to ST25R3914-AQFT. ST25R3915-AQFT omits the AAT circuitry but retains identical RF performance, dual antenna drivers, and all other features. Antenna tuning must be performed externally or via host-controlled calibration algorithms using phase/amplitude measurement registers.
ST25R3915-AQFT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- ST25R
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- RFID Reader
- Frequency:
- 13.56MHz
- Standards:
- ISO 14443
- Interface:
- SPI
- Voltage - Supply:
- 2.4V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
ST25R3915-AQFT FAQ
1.How can I place an order for ST25R3915-AQFT through Aetrix?
Please submit a Request for Quotation (RFQ) for ST25R3915-AQFT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ST25R3915-AQFT reliable?
The price and inventory of ST25R3915-AQFT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST25R3915-AQFT is usually 5 days.
3.What payment methods are accepted for ST25R3915-AQFT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST25R3915-AQFT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST25R3915-AQFT?
ST25R3915-AQFT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST25R3915-AQFT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ST25R3915-AQFT?
For technical support, including ST25R3915-AQFT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST25R3915-AQFT requirements.
6.How does Aetrix verify that ST25R3915-AQFT is sourced from the original manufacturer or authorized distributors?
All ST25R3915-AQFT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ST25R3915-AQFT meets industry standards.
7.What is the process for return or replacement of ST25R3915-AQFT?
All ST25R3915-AQFT units undergo pre-shipment inspection (PSI). If there is an issue with ST25R3915-AQFT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ST25R3915-AQFT part is unused and in its original packaging.
Return procedure for ST25R3915-AQFT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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