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STMicroelectronics ST25R3918-AQET
- Part No.:
- ST25R3918-AQET
- Manufacturer:
- STMicroelectronics
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
ST25R3918-AQET.pdf
- Description:
- Linear IC's
- Quantity:
- Payment:
- Shipping:
Inventory:1,789
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Product details
Overview
ST25R3918-AQET from STMicroelectronics is a multi-purpose NFC transceiver IC supporting reader/writer, card emulation, and passive peer-to-peer modes. It operates across NFC-A/B/V/F standards (up to 848 kbit/s), features dynamic power output (DPO), active wave shaping (AWS), and noise suppression receiver (NSR), and targets secure access control, contactless payment terminals, and industrial asset tagging.
For engineers reviewing the ST25R3918-AQET datasheet, ST25R3918-AQET pinout, ST25R3918-AQET application, or ST25R3918-AQET equivalent, key selection criteria include ISO14443A/B/V/F protocol support, dual-antenna drive capability, integrated AM/PM/I/Q demodulation, low-power passive target operation, and 2.6–5.5 V wide-supply operation across –40 °C to +105 °C.
Technical Context
The ST25R3918-AQET integrates a fully programmable transmitter with adjustable ASK modulation depth (5–40%), dual-path receiver with automatic channel selection, and phase/amplitude detector enabling real-time antenna tuning. Its on-chip A/D converter and RSSI measurement support closed-loop field control.
It implements three distinct operating domains: initiator (reader) mode with configurable bit rates and collision handling; passive target (emulation) mode compliant with MIFARE Classic® and NFCIP-1; and listen mode for ultra-low-power wake-up detection. All modes share a unified register map and FIFO-based host interface.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| NFC Protocols | NFC-A/ISO14443A & NFC-B/ISO14443B up to 848 kbit/s; NFC-V/ISO15693 up to 53 kbit/s; NFC-F/FeliCa™ card emulation |
| Modulation Support | Adjustable ASK depth (5–40%); AM/PM and I/Q demodulation with baseband summation or auto-channel selection |
| Supply Range | 2.6–5.5 V at –40 °C to +105 °C; peripheral I/O supply 1.65–5.5 V - enables direct interfacing with 1.8 V/3.3 V/5 V MCUs |
| Host Interface | SPI up to 10 Mbit/s; I²C Fast-mode Plus (1 Mbit/s) and High-speed mode (3.4 Mbit/s); 512-byte FIFO reduces host interrupt load |
| Antenna Drive | Supports two independent single-ended antennas; on-chip voltage/phase/RSSI measurement enables real-time antenna matching |
| Low-Power Features | Capacitive/inductive card detection in <100 µA; passive target modes with <15 µA standby current; wake-up timer with RC oscillator |
| Protection & Stability | Dynamic Power Output (DPO) maintains field strength within regulatory limits; Active Wave Shaping (AWS) suppresses overshoot/undershoot |
Pinout & Package
VFQFPN32 (5 × 5 mm, 0.5 mm pitch) package with wettable flanks, optimized for automated optical inspection and high-density PCB layouts.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD | Main power supply input | Accepts 2.6–5.5 V; powers analog/RF core and internal regulators |
| VDDIO | I/O supply input | Independent 1.65–5.5 V rail for SPI/I²C logic compatibility |
| ANT1P / ANT1N | Differential antenna port 1 | Configurable as single-ended via external balun; supports 13.56 MHz RF transmission/reception |
| ANT2P / ANT2N | Differential antenna port 2 | Enables dual-antenna systems (e.g., front/back coverage or diversity switching) |
| IRQ | Interrupt request output | Open-drain signal indicating FIFO status, RX completion, field detection, or error events |
| SCLK / SDA / SCL / MOSI / MISO / CS | Serial interface signals | Shared pins for SPI (4-wire) or I²C; mode selected via hardware strap or register configuration |
| XTAL_IN / XTAL_OUT | Crystal oscillator connection | Drives internal 27.12 MHz clock with fast start-up; supports external clock injection |
Key Features
| Feature | Design Value |
|---|---|
| Noise Suppression Receiver (NSR) | Enables reliable communication in electrically noisy environments (e.g., industrial gateways, POS terminals near motors or displays) |
| Dynamic Power Output (DPO) | Real-time field strength regulation ensures compliance with ETSI EN 300 330 and FCC Part 15 without external feedback circuitry |
| Active Wave Shaping (AWS) | Reduces RF waveform distortion at antenna edges, minimizing EMI and improving interoperability with legacy tags |
| Automatic Gain Control + Squelch | Maximizes SNR across varying tag distances and coupling conditions; eliminates manual gain tuning in firmware |
| On-Chip Phase/Amplitude Measurement | Enables antenna impedance monitoring and adaptive matching without external ADC or RF sampling circuits |
Applications
| Access Control System | POS Payment Terminal |
|---|---|
Use Scenario: Secure door entry using NFC-enabled credentials (e.g., employee badges, mobile wallets). IC Role / Device Role / Timing Role: Acts as ISO14443A/B reader initiating polling, anti-collision, and secure authentication handshake. Use Value: DPO and NSR ensure consistent read range across metal-door installations and electromagnetic interference from building infrastructure. |
Use Scenario: Contactless payment processing in retail point-of-sale devices. IC Role / Device Role / Timing Role: Emulates EMV-compliant contactless card (NFC-A/F) while supporting fast transaction handshakes via I²C host interface. Use Value: Integrated regulators and PSRR enhancement reduce need for external LDOs; 10 Mbit/s SPI enables rapid firmware updates during terminal provisioning. |
| Industrial Asset Tagging | Smart Home Hub |
Use Scenario: Maintenance tracking of factory equipment using NFC tags embedded in harsh environments. IC Role / Device Role / Timing Role: Operates in low-power listen mode to detect passive tags; uses capacitive card detection to minimize false triggers. Use Value: –40 °C to +105 °C ambient rating and robust RF front-end allow deployment near motors, welders, or HVAC units without derating. |
Use Scenario: Unified NFC interface in residential smart hubs for device pairing, firmware updates, and user onboarding. IC Role / Device Role / Timing Role: Supports simultaneous reader and card emulation modes to enable tap-to-pair and tap-to-configure workflows. Use Value: Dual-antenna drive capability allows spatially separated antennas for improved UX (e.g., top-panel tap zone + side-panel service port). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NFC transceiver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| NXP PN7160 | Lacks dual-antenna support; no on-chip phase/amplitude measurement; lower max SPI speed (5 Mbit/s) | Better suited for cost-sensitive consumer electronics where single-antenna design suffices | Select when BOM cost is prioritized over field diagnostics and multi-zone coverage |
| Infineon SLI13 | Supports only ISO14443A/B; no NFC-V/FeliCa™ emulation; no AWS or DPO features | Targeted at basic RFID reader applications without regulatory field-strength constraints | Select only for legacy ISO14443-only deployments requiring minimal feature set |
Compared with PN7160 and SLI13, ST25R3918-AQET uniquely delivers full NFC Forum protocol coverage, real-time antenna diagnostics, and field-regulated transmission-making it the only choice for industrial-grade, multi-standard, and dual-antenna NFC systems requiring EMI resilience and regulatory compliance.
Availability
ST25R3918-AQET is available at Aetrix Electronics and suitable for access control systems, POS payment terminals, industrial asset tagging, and smart home hubs requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for ST25R3918-AQET 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, designing and manufacturing microcontrollers, power management ICs, sensors, and connectivity solutions for industrial, automotive, and consumer markets.
The ST25 family targets secure, low-power NFC and RFID applications, with the ST25R3918 specifically engineered for multi-protocol, high-reliability, and field-diagnostic-capable transceivers in mission-critical embedded systems.
FAQ
What is the maximum data rate supported by ST25R3918-AQET in reader mode?
The ST25R3918-AQET supports up to 848 kbit/s in NFC-A and NFC-B reader modes (ISO14443A/B), and 53 kbit/s in NFC-V (ISO15693) mode. This matches the highest physical layer speeds defined in the NFC Forum specifications and enables fast tag enumeration and bulk data transfer in applications like firmware update over NFC.
Does ST25R3918-AQET require an external crystal, or can it use an internal oscillator?
ST25R3918-AQET requires an external 27.12 MHz crystal connected to XTAL_IN/XTAL_OUT for RF clock generation; the internal RC oscillator is used only for wake-up timer and low-power system timing-not for RF operations. Crystal start-up time is optimized for fast initialization in battery-powered devices.
Can ST25R3918-AQET simultaneously operate as both reader and card emulator?
No-ST25R3918-AQET supports reader/writer, card emulation, and passive peer-to-peer modes, but only one mode is active at a time. Mode switching is performed via register writes and takes <100 µs; however, true concurrent operation (e.g., reading a tag while emulating another) is not supported by hardware or firmware.
How does Dynamic Power Output (DPO) improve regulatory compliance?
DPO continuously monitors antenna voltage and adjusts driver output in real time to maintain magnetic field strength within ETSI/FCC limits-eliminating the need for external field probes or manual calibration. This ensures consistent compliance across temperature, voltage, and antenna aging effects without firmware intervention.
ST25R3918-AQET Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Bulk
- Product Status:
- Active
- Type:
- RFID Reader/Transponder
- Frequency:
- 13.56MHz
- Standards:
- FeliCa, ISO 14443A, ISO 14443B, ISO 15693, Mifare, NFC
- Interface:
- I2C, SPI
- Voltage - Supply:
- 2.6V ~ 5.5V
- Operating Temperature:
- -40°C ~ 105°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 32-VFQFPN (5x5)
ST25R3918-AQET FAQ
1.How can I place an order for ST25R3918-AQET through Aetrix?
Please submit a Request for Quotation (RFQ) for ST25R3918-AQET 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 ST25R3918-AQET reliable?
The price and inventory of ST25R3918-AQET are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST25R3918-AQET is usually 5 days.
3.What payment methods are accepted for ST25R3918-AQET?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST25R3918-AQET transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST25R3918-AQET?
ST25R3918-AQET orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST25R3918-AQET 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 ST25R3918-AQET?
For technical support, including ST25R3918-AQET datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST25R3918-AQET requirements.
6.How does Aetrix verify that ST25R3918-AQET is sourced from the original manufacturer or authorized distributors?
All ST25R3918-AQET 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 ST25R3918-AQET meets industry standards.
7.What is the process for return or replacement of ST25R3918-AQET?
All ST25R3918-AQET units undergo pre-shipment inspection (PSI). If there is an issue with ST25R3918-AQET, 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 ST25R3918-AQET part is unused and in its original packaging.
Return procedure for ST25R3918-AQET:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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