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STMicroelectronics ST25R3920B-AQWT
- Part No.:
- ST25R3920B-AQWT
- Manufacturer:
- STMicroelectronics
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ST25R3920B-AQWT.pdf
- Description:
- MOTOR CONTROL CONNECTOR EXPANSIO
- Quantity:
- Payment:
- Shipping:
Inventory:2,152
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Product details
Overview
ST25R3920B-AQWT from STMicroelectronics is an AEC-Q100 qualified automotive NFC reader IC designed for CCC digital key and center console applications. It supports full NFC Forum modes (reader/writer, card emulation, active/passive peer-to-peer), complies with EMVCo® PCD L1 v3.2a, and operates across NFC-A/B/F/V protocols at data rates up to 848 kbit/s. Its integrated antenna tuning, noise suppression receiver, and dynamic power output enable robust operation in electrically noisy vehicle cabins.
For engineers reviewing the ST25R3920B-AQWT datasheet, ST25R3920B-AQWT pinout, ST25R3920B-AQWT application, or ST25R3920B-AQWT equivalent, this device delivers certified automotive-grade NFC performance with SPI/I²C host interface support, on-chip regulators, and real-time antenna voltage/phase measurement - critical for secure digital key handshaking and low-latency proximity detection.
Technical Context
The ST25R3920B integrates a dual-channel I/Q demodulator with baseband summation or automatic channel selection, enabling reliable signal recovery under EMI-rich conditions. Its noise suppression receiver (NSR) and automatic gain control with squelch maximize SNR in automotive environments where RF interference from motors and inverters is prevalent.
Transmitter architecture includes active wave shaping (AWS) to minimize overshoot/undershoot and dynamic power output (DPO) for precise field strength regulation per EMVCo® limits. The block-level implementation of automatic antenna tuning (AAT) via integrated variable capacitor eliminates external tuning components and enables real-time impedance matching during operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Compliance | EMVCo® PCD L1 v3.2a analog/digital compliant - ensures interoperability with payment terminals and certified access systems. |
| Data Rates | NFC-A/B up to 848 kbit/s; NFC-F up to 424 kbit/s; NFC-V up to 53 kbit/s - supports high-speed tag interrogation and peer-to-peer exchange. |
| Supply Range | 2.6–5.5 V at -40 °C to +105 °C - meets automotive extended temperature requirements without external LDOs. |
| Host Interface | SPI up to 5 Mbit/s; I²C Fast-mode Plus (1 Mbit/s) and High-speed mode (3.4 Mbit/s) - enables low-latency command/response with microcontrollers. |
| FIFO Depth | 512-byte hardware FIFO - reduces host CPU overhead during burst data transfers like NDEF message exchange. |
| Antenna Support | Drives two independent single-ended antennas - allows dual-zone sensing (e.g., door handle + center console) from one IC. |
| Modulation Control | Adjustable ASK depth (0–82%) - fine-tunes field coupling for diverse tag types and metal-mount scenarios. |
Pinout & Package
VFQFPN32 (5 × 5 mm, 0.5 mm pitch) package with wettable flanks for automated optical inspection. Exposed thermal pad improves thermal dissipation in sealed automotive enclosures.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Main supply input | Accepts 2.6–5.5 V; powers internal regulators and RF stages - no external DC-DC required for typical 3.3 V or 5 V automotive rails. |
| VDDIO | I/O supply input | Independent 1.65–5.5 V rail - enables direct interfacing with 1.8 V, 3.3 V, or 5 V host MCUs without level shifters. |
| RFOUT_A / RFOUT_B | Differential RF output | Drives external matching network for antenna A or B - supports simultaneous dual-antenna operation with software-selectable path. |
| RFIN_A / RFIN_B | Differential RF input | Receives backscattered signals from NFC tags on either antenna - enables true diversity reception and collision avoidance. |
| SCLK / MOSI / MISO / NSS | SPI interface signals | Full-duplex 4-wire SPI up to 5 Mbit/s - optimized for deterministic timing in safety-critical firmware stacks. |
| SCL / SDA / INT | I²C interface and interrupt | INT asserts on FIFO threshold, field detection, or error - enables event-driven host polling and low-power wake-up. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic Antenna Tuning (AAT) | On-the-fly capacitor adjustment via internal DAC - maintains resonance despite temperature drift or mechanical stress on PCB-mounted antennas. |
| Noise Suppression Receiver (NSR) | Adaptive filtering rejects broadband EMI from DC-DC converters and motor drivers - sustains link integrity at <10 cm range in EV cabins. |
| Dynamic Power Output (DPO) | Real-time field amplitude regulation against EMVCo® ±10% limit - eliminates need for manual calibration or external power metering. |
| Integrated EMD Handling | Hardware-accelerated EMVCo® electro-magnetic disturbance mitigation - satisfies PCD L1 v3.2a immunity test requirements without host firmware intervention. |
| Phase & Amplitude Detection | On-chip measurement of antenna voltage phase/amplitude and RSSI - enables metal-compensation algorithms and proximity-based authentication logic. |
Applications
| CCC Digital Key Authentication | Automotive Center Console NFC |
|---|---|
Use Scenario: Smartphone-based vehicle unlock and engine start via Bluetooth Low Energy handshake followed by NFC challenge-response. IC Role / Device Role / Timing Role: Acts as EMVCo®-compliant PCD initiating secure APDU exchange with smartphone's secure element in card emulation mode. Use Value: Enables sub-100 ms mutual authentication with tamper-resistant session keys - meeting Car Connectivity Consortium security baseline for digital keys. |
Use Scenario: User taps phone or fob on center console to launch infotainment profile, load preferences, or initiate wireless charging negotiation. IC Role / Device Role / Timing Role: Operates in listen mode with ultra-low-power wake-up timer, detecting presence before full RF activation. Use Value: Achieves <5 µA standby current with field detection - extends system battery life during vehicle sleep mode while maintaining instant responsiveness. |
| Multi-Zone Vehicle Access | Secure OTA Firmware Update Trigger |
Use Scenario: Simultaneous NFC detection at door handle (antenna A) and B-pillar (antenna B) to determine user entry point and pre-condition climate zones. IC Role / Device Role / Timing Role: Drives two independent single-ended antennas with synchronized TX/RX timing - avoids cross-talk via time-division multiplexing. Use Value: Eliminates need for two discrete NFC readers - reduces BOM cost and PCB area while enabling spatial-aware access control logic. |
Use Scenario: Technician places certified service tool near vehicle's OBD-II port to trigger authenticated firmware update sequence. IC Role / Device Role / Timing Role: Performs passive target mode with FeliCa™ protocol to verify tool's cryptographic certificate before enabling CAN FD download path. Use Value: Provides hardware-rooted identity binding between physical tool and ECU - prevents unauthorized reprogramming attempts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NFC reader applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NXP PN7160 | Lacks AEC-Q100 qualification; no integrated EMVCo® EMD handling; max 424 kbit/s NFC-F; no dual-antenna drive capability. | Targeted at consumer electronics and industrial HMI - not validated for automotive cabin EMI or CCC digital key certification. | Select when cost-sensitive non-automotive NFC reader design requires minimal external components and lower data rate suffices. |
| Infineon SLI13 | AEC-Q100 Grade 2 (-40 °C to +105 °C); supports only NFC-A/B; no NFC-F/FeliCa™ or peer-to-peer; no on-chip antenna tuning. | Designed for basic keyless entry transponders - lacks protocol breadth and field control features needed for digital key handshaking. | Select for legacy 13.56 MHz RFID reader upgrades where FeliCa™, peer-to-peer, or adaptive tuning are unnecessary. |
Compared with PN7160 and SLI13, the ST25R3920B-AQWT uniquely combines AEC-Q100 Grade 1 operation, full NFC Forum protocol stack, dual-antenna support, and hardware-accelerated EMVCo® compliance - making it the only single-chip solution qualified for CCC digital key deployment in production vehicles.
Availability
ST25R3920B-AQWT is available at Aetrix Electronics and suitable for automotive digital key systems, center console HMI interfaces, and multi-zone vehicle access modules requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for ST25R3920B-AQWT 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 headquartered in Geneva, Switzerland, with manufacturing facilities across Europe, Asia, and the Americas. It develops automotive-grade ICs with emphasis on functional safety, reliability, and regulatory compliance.
The ST25R series targets automotive NFC infrastructure, specifically addressing the stringent electromagnetic compatibility, temperature resilience, and certification requirements of digital key and secure proximity applications in modern vehicles.
FAQ
Is ST25R3920B-AQWT qualified for automotive use?
Yes. The ST25R3920B-AQWT is AEC-Q100 qualified for Grade 1 operation (-40 °C to +105 °C ambient), with built-in protection against automotive EMI sources including DC-DC converters and motor inverters. Its EMVCo® PCD L1 v3.2a compliance and integrated noise suppression receiver meet OEM requirements for digital key deployment in production vehicles.
Does ST25R3920B-AQWT support both SPI and I²C host interfaces simultaneously?
No. The ST25R3920B-AQWT supports either SPI or I²C, selected at power-on via configuration pins (IO_CFG1/IO_CFG2). Both interfaces are fully functional and offer high-speed operation - SPI up to 5 Mbit/s and I²C up to 3.4 Mbit/s in High-speed mode - but only one can be active per system configuration.
Can ST25R3920B-AQWT drive antennas directly without external matching components?
It integrates a variable capacitor for automatic antenna tuning (AAT) but still requires an external matching network (typically L/C tank) between RFOUT and the antenna. The AAT dynamically adjusts capacitance to maintain resonance, reducing sensitivity to PCB layout variations and environmental shifts - however, discrete inductors and capacitors remain necessary for impedance transformation and harmonic filtering.
What NFC protocols does ST25R3920B-AQWT support in card emulation mode?
In card emulation mode, the ST25R3920B-AQWT supports NFC-A/ISO14443A at 106 kbit/s and NFC-F/FeliCa™ at 212/424 kbit/s. It does not support ISO14443B or ISO15693 in card emulation - those protocols are supported only in reader/writer mode. This aligns with CCC digital key specifications, which mandate NFC-A and FeliCa™ for secure element communication.
ST25R3920B-AQWT 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/Transponder
- Frequency:
- 13.56MHz
- Standards:
- FeliCa, NFS
- Interface:
- I2C, SPI
- Voltage - Supply:
- 2.6V ~ 5.5V
- Operating Temperature:
- -40°C ~ 105°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 32-VFQFPN (5x5)
ST25R3920B-AQWT FAQ
1.How can I place an order for ST25R3920B-AQWT through Aetrix?
Please submit a Request for Quotation (RFQ) for ST25R3920B-AQWT 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 ST25R3920B-AQWT reliable?
The price and inventory of ST25R3920B-AQWT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST25R3920B-AQWT is usually 5 days.
3.What payment methods are accepted for ST25R3920B-AQWT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST25R3920B-AQWT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST25R3920B-AQWT?
ST25R3920B-AQWT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST25R3920B-AQWT 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 ST25R3920B-AQWT?
For technical support, including ST25R3920B-AQWT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST25R3920B-AQWT requirements.
6.How does Aetrix verify that ST25R3920B-AQWT is sourced from the original manufacturer or authorized distributors?
All ST25R3920B-AQWT 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 ST25R3920B-AQWT meets industry standards.
7.What is the process for return or replacement of ST25R3920B-AQWT?
All ST25R3920B-AQWT units undergo pre-shipment inspection (PSI). If there is an issue with ST25R3920B-AQWT, 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 ST25R3920B-AQWT part is unused and in its original packaging.
Return procedure for ST25R3920B-AQWT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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