ST25R3920B Product Presentation

NFC Automotive Reader – Key messages

The ST25R3920B is the Master device and provides power, enabling phone readout even with an empty battery. It facilitates communication with NFC-enabled mobile phones (over 70% adoption rate for iOS or Android).

Key Advantages:

• >1.6W power for excellent interaction range and smallest antenna sizes.
• Advanced features, faster time to market, and simplified electromagnetic immunity.
• Best customer experience by tapping a phone to the car.

Applications: Payment, Car access, Car start.

(Image description: A montage of images showing a hand unlocking a car door with a phone, a car charging station, and a person holding a smartphone.)

ST25R3920B Use Cases

• Car access: Compliant to CCC DK2.0 specs.
• NFC card protection: Protects NFC cards like credit cards and access cards from powerful Qi fields.
• Car start: Compliant to CCC DK2.0 specs.
• Car sharing: Allows shared key with preference settings.
• Consumable authentication: Increases safety, traceability, and convenience of replacement parts.
• Payment: In-car or external payment for electric charge.

(Image description: A grid of images illustrating the various use cases: car access, NFC card protection, car start, car sharing, consumable authentication, and payment.)

ST25R Key Performance Parameters

• Good range: Consistent experience with Dynamic Power Output (DPO). High output power, automatically adjusted to optimize power transfer and stay within certification limits.
• Low power consumption: Capacitive & Inductive Wakeup (CIWU). Increased battery lifetime during key detection. Capacitive and Inductive wakeup allow for low power consumption while in card detection mode.
• Noise immunity: Noise Suppression Receiver (NSR). Increased immunity to interference from noise sources, simplifying electromagnetic immunity and easing certification.
• Distinguish phone from NFC card: Heartbeat algorithm. Highest detection rate of phones for NFC card protection with Qi chargers.

(Image description: Four columns detailing key performance parameters: Good range, Low power consumption, Noise immunity, and Distinguish phone from NFC card, each with descriptive icons.)

ST25R NFC / HF readers product family

Abbreviations: VHBR: Very High Baud Rate, P2P: Peer to Peer mode, AAT: Automatic Antenna Tuning, AWS: Active Wave Shaping, DPO: Dynamic Power Output, CIWU: Capacitive & Inductive Wakeup, EMD: Automatic EMD suppression, DSA: Drive Slope Adjustment, NSR: Noise Suppression Receiver, IWU: Inductive Wakeup

ST25R3920B CCC digital key and car center console

Use cases:

• Ideal for Car Consortium Consortium Digital Key (CCC DK) applications.
• IoT and pairing in the car (center console).

Key Features:

• NFC Forum Device Universal Device and CR13 CCC Reader device.
• AEC-Q100 grade 1, -40°C to 105°C ambient temperature range.
• 1.6W output power with Dynamic Power Output.
• Improved Active Waveshaping, Noise Suppression Receiver.
• EMVCo 3.1 compliant for EV charging and in-car payment.
• Unique Heartbeat algorithm for NFC card/phone detection.

Key Benefits:

• Low power operation & Standby mode (capacitive wake-up).
• Works in challenging environments like small antennas.

ST25R3920B benefits

• NSR: Noise Suppression Receiver: More robust against noise, decoding at high noise level with up to 19.3dB better SNR. Cheap/noisy LCD possible for EMVCo POS terminals.
• Heartbeat Algorithm: Highest detection rate of phones for NFC card protection with Qi chargers.
• DSA: Driver Slope Adjustment: Easier FCC approval. Programmable Push/Pull driver slope minimizes high frequency EMC noise.
• AWS: Active Waveshaping: Adjustment of waveshape to remove under/overshoot simply by parameter setting and no need to redo matching. Faster/easier EMVCo analog approval.

(Image description: Visual representations of NSR, Heartbeat Algorithm, DSA, and AWS features.)

ST25R3920B benefits

• Large FIFO; Automatic EMD: Reduced/faster SW integration effort. Complete frames can be transmitted and received without SW interaction. Time critical EMD suppression is handled automatically.
• Improved RF Performance: Larger operating volume/ smaller antenna. Unrivaled RX sensitivity with high output power delivers maximum margin for challenging antenna designs.
• Low power card detection: Use of inductive wakeup allows for low power consumption while in card detection mode.
• DPO: Dynamic Power Output: Increase Efficiency and achieve min/max Limits. The output power is adjusted automatically to reduce power and stay within certification limits.

(Image description: Visual representations of Large FIFO/Automatic EMD, Improved RF Performance, Low power card detection, and DPO features.)

Digital Key Master and Anchor Architecture

(Diagram description: A system architecture diagram showing the Key (Smartcard ST31), Anchor (e.g., door-handle with ST25R3920B and MCU), and Master ECU (Standalone Immobilizer module with SPC58 and ST33 eSE). Connections are shown via SPI/PC, CAN, and In-vehicle Networking.)

ST25 Reader DPO: Dynamic Power Output

• Achieve min/max power limits easier: The ST25R series allows adjustment of the output power dynamically via Dynamic Power Output.
• Optimal performance from weak to strong card response: ST25R series allows adoption to different power levels of card responses via Active Gain Control.
• Improved noise immunity: Squelch feature allows scaling the signal level to have improved immunity against noise.

(Diagram description: A bar chart illustrating power levels: Reduced Power Level, Normal Power Level, and Increased Power Level, with hysteresis and thresholds.)

ST25 Reader DPO: Dynamic Power Output

DPO of reader will keep power levels within requirements & limits.

(Diagram description: A line graph showing Field Strength [A/m] versus Distance [cm]. Lines represent 'without DPO' and 'with DPO' power adjustments, illustrating how DPO helps stay within NFC Forum Damage Limit, Maximum Limit, and Minimum Limit.)

NSR: noise suppression receiver

• Proper decoding: Proper decoding still possible even though LCD noise level exceeds card signal strength. ANS jumps in as soon as the receiver locks on a card response.
• Noise immunity compared to non NSR: Type A 106 display noise immunity improved by a factor of 3.3 vs ST25R3911B. Type B 106 display noise immunity improved by a factor of 9.2 vs ST25R3911B.

(Image description: A waveform display showing 'LCD Noise' and 'Card Response', illustrating the effect of the NSR feature.)

AWS: active waveshaping

• The improved active waveshape (AWS) function will reduce over- and undershoots even easier than before.
• The function is easily enabled by using the bits in the corresponding registers. 2 registers and 14 bits for each over and under shoot protection are available and allow for easy adjustment.
• To an acceptable level in challenging designs.

(Image description: Two waveform comparison charts showing 'Traditional A 106 modulation pulse' with overshoot and 'Improved A106 modulation pulse with Over/Undershoot Protection' with reduced overshoot. Text indicates that over/undershoots can be solved with register settings, no rematching of antenna required.)

EMD: automatic EMD suppression

• Automatic PCD EMD handling: When the ST25R3916B receives a PICC frame, it is checked for transmission errors. Transmission errors are detected in real time, and if the number of received bytes with a transmission error is less than 4, the PCD ignores the transmission and prepares to receive a new PICC frame.
• Increased Robustness: EMD handling enhances the robustness of contactless communication between ST25R3916B/17B and the PICC against PICC-generated electromagnetic disturbance (EMD).

(Image description: A waveform capture showing 'DUT Command Pulse' and 'RefPICC response' with highlighted EMD sections.)

Low power card detection

• Internal wakeup circuitry: The ST25R3916B/17B includes a fully programmable wakeup scheme based on inductive sensing. All relevant parameters like cycle time & sensitivity can be programmed.

(Diagram description: An illustration showing inductive sensing for low power card detection.)

Reduce power consumption while offering good detection range

Consider reaction time/sensitivity of the system.

(Diagram description: A diagram illustrating system timing: Card Polling (can be set), System time (varies on application), and Time to action (expected to be <500ms for human interaction). It also shows Sensitivity (distance of detection).)

Reduce power consumption while offering good detection range

Consider reaction time/sensitivity of the system.

Parameters:

• Card Polling: Can be set.
• Timer period: Time the IC stays in Sleep mode before checking for a card. Can be set from 10 to 800ms in 16 steps.
• System time: Varies on application.
• Time to action: Usually expected to be <500ms for human interaction.
• Sensitivity: Distance of detection. Delta (window size) sets sensitivity in 256 steps.
• Auto averaging: Higher noise immunity or compensation for slow environmental changes. Can be set to average over the last 4/8/16/32 cycles.
• Automatic reference measurement: Measures environmental influence to the capacitive sensor or antenna. Used to calibrate the wakeup system at system start or any required time.

Evaluation boards & ecosystem

(Image description: A photograph of a technician working on electronic components on a circuit board, with various testing equipment in the background.)

Competitor analysis

ST25R3920B vs. Competition

Feature Descriptions:

• AAT (Automatic Antenna Tuning): Compensates temperature, production drift; Improves communication with metal phones/watch.
• NSR (Noise Suppression Receiver): Improves immunity against external noise sources; Improves communication with phones/watch.
• AWS (Active Waveshaping): Improves waveshapes and communication with phones/watch.
• DPO (Dynamic Power Output): Dynamically adjusts output power to requirements.

ST25R3920B rich eco-system

• Development Kits: Discovery kits based on STM32 MCU, STM32 Nucleo boards ecosystem, STM32Cube software ecosystem.
• Antenna Design: Antenna e-design tool, Schematic, BOM, Gerber files.
• Software Tools: PC software tool ST25, MCU drivers firmware.
• Documentation & Community: Documentation, e2e community, Webinar / MOOC, Training.

ST25R3916B* family evaluation boards

• STEVAL-25R3916B ST25R3916B discovery kit: High perf NFC universal device and EMVCo reader, 66x66mm 2 turns antenna etched on PCB, STM32L476 ULP 32-bit MCU, Micro-USB connector, Additional UART / I²C Host interfaces, NFC SPI and JTAG/SWD points.
• X-NUCLEO-NFC08A1 ST25R3916B Nucleo shield: High perf NFC universal device and EMVCo reader, 47x34mm 4 turns antenna etched on PCB, Compatible with STM32 Nucleo boards, Equipped with Arduino™ UNO R3 connector.
• ST25R3916B-EMVCO ST25R3916B EMVCO kit: High perf NFC universal device and EMVCo reader, 51x27mm 3 turns antenna etched on PCB, STM32L476 ULP 32-bit MCU, Micro-USB connector, Comprehensive Device Test Environment (DTE) for EMVCo Level 1 FW control.

(*Discovery kit and Nucleo shield are also valid for ST25R3917B and ST25R3920B)

SW ecosystem for ST25 HF Readers

(Image description: A person using a payment terminal with a credit card.)

ST25R software overview

Software development tools for ST25R HF Reader IC

Graphical User Interface (GUI):

• GUI for ST25R PC software for Windows.
• On request: GUI for ST25R EMVCo PC software for Windows.

Firmware:

• DISCO board: DISCO // EMVCo Firmware & source, RFAL Firmware & source, STM32, ST25R, SPI.
• NUCLEO board: NUCLEO Firmware & source, RFAL Firmware & source, STM32, ST25R, SPI, LOG file.

ST solutions: ST25 HF Reader

ST25R RFAL SW suite

ST NFC Reader "RFAL" software suite

• Comprehensive device driver and middleware to build NFC enabled applications for reader devices based on ST25R NFC Readers.
• Written in pure ANSI C.
• Straightforward portability across different platforms (MCU/RTOS/OS) with non-blocking API.
• Compliant with main HF/NFC standards (NFC Forum, ISO).
• Source code example implementations available: embedded (STM32, STM8 device, SPC5 on request) and Linux® (Raspberry Pi).
• Easy callback function for proprietary NFC technologies on application layer like Apple ™ Mfi (delivered under Mfi conditions) and other technologies.
• ST25R3916 RFAL SW (STSW-ST25RFAL002) and ST25R3911B RFAL SW (STSW-ST25RFAL01).

ST solutions: ST25 HF Reader

ST25R PC GUI software

ST NFC Reader "Discovery” software suite

• Supports several RF protocols (ISO14443-A / NFC-A, ISO14443-B / NFC-B, FeliCa™ / NFC-F and ISO15693 / NFC-V).
• Active P2P (peer to peer) according to ISO18092, including SNEP.
• Card emulation in NFC-A (106kbps) and NFC-F (212 and 424kbps).
• Wakeup feature, analog configuration and register access of ST25R3916.
• Support of Automatic Antenna Tuning (AAT) & Dynamic Power Output (DPO).
• Access to all ST25 Tag features thanks to ST25PC NFC SW (STSW-ST25PC001).
• ST25R3916 PC GUI SW (STSW-ST25R010) and ST25R3911B PC GUI SW (STSW-ST25R001).

ST solutions: ST25 HF Reader

ST25R Firmware for MCU

Firmware for ST25R Discovery, Nucleo & EMVCo boards

(Diagram description: A software architecture diagram showing layers like Utilities, Applications, CMSIS, Middleware, STM32Cube HAL, Drivers, Hardware components, Board support packages, and ST25R NFC reader IC, interacting with different boards like ST25 Discovery board, ST25 Nucleo Board, and ST25 EMVCo Board.)

Content:

• Complete set of source files to compile firmware for development boards (Discovery, Nucleo...).
• Reader / Writer demonstration: Tag inventory, read and write (all NFC standard protocols supported), Dynamic power output, NFC Forum NDEF messages.
• Card emulation demonstration: NFC Type 4A Tag emulation (all tag types supported in USB mode), NFC Forum NDEF messages, Possibility to be written by a reader or by a smartphone.
• Peer to peer (P2P) demonstration.
• EMVCo Layer 1 support FW, on request.
• ST25R3916 Disco kit FW (STSW-ST25R011), ST25R3916 Nucleo board FW (X-CUBE-NFC6) and ST25R3911B Disco kit FW (STSW-ST25R002).

ST solutions: ST25 HF Reader

ST25R antenna matching software kit

ST NFC Reader "Antenna Matching" software kit

• Comprehensive antenna matching tool with GUI to find the right external component values for a chosen configuration.
• Available for the entire ST25R HF Reader product line.
• Allows configuration with or without AAT functionality.
• Integrates circuit simulator (QUCS), automatic component value selection and generates the Smith Chart.
• Standalone version for Windows PC and online tool available.
• Antenna Matching tool for ST25R NFC/HF Reader (STSW-ST25R004).

(Image description: Screenshot of the ST25R Antenna Matching Tool GUI, showing various parameters for antenna configuration and matching.)

Solutions for NFC / RFID Tags & Readers

ST25 SIMPLY MORE CONNECTED

(Image description: A cityscape with interconnected icons representing cloud, phone, headphones, house, bicycle, and NFC/RFID tags, symbolizing connectivity.)