Features
• AEC-Q100 qualified
• Operating modes
– Reader/writer
– Card emulation
– Active and passive peer to peer
• RF communication
– EMVCo® 3.1a analog and digital compliant
– NFC-A / ISO14443A up to 848 kbit/s
– NFC-B / ISO14443B up to 848 kbit/s

Applications
The ST25R3920B device is suitable for a wide range of NFC and HF RFID applications,
among them
• NFC Forum compliant NFC universal device
• EMVCo 3.1a compliant contactless payment terminal
• ISO14443 and ISO15693 compliant general purpose NFC device
• FeliCa™ reader / writer
• Support all five NFC Forum Tag types in reader mode
• Support all common proprietary protocols, such as Kovio, CTS, B’.

Description
The ST25R3920B is an automotive grade high performance NFC universal device
supporting NFC initiator, NFC target, NFC reader and NFC card emulation modes.
Designed for CCC (car connectivity consortium) digital key applications, the ST25R3920B
enables fast product development for car access/start applications in areas like door handle
or center console, and enables additional functionality, like pairing or NFC card protection
combined with a Qi charger. Being very robust and noise tolerant while at the same time
reducing electromagnetic emission, the device works even under harsh conditions, enabling
an easier certification.
The device includes an advanced analog front end (AFE) and a highly integrated data
framing system for ISO18092 passive and active initiator, ISO 18092 passive and active
target, NFC-A/B (ISO14443A/B) reader including higher bit rates, NFC-F (FeliCa™) reader,
NFC-V (ISO15693) reader up to 53 kbps, and NFC-A / NFC-F card emulation.
Special stream and transparent modes of the AFE and framing system is used to implement
other custom protocols in reader or card emulation modes.
The ST25R3920B features high RF power with dynamic power output to directly drive
antennas at high efficiency, achieving large interaction distance even with small antenna
sizes common in door handles. The device include additional features, making it
incomparable for low power applications. It offers low power card detection by performing a
measurement of the amplitude or phase of the antenna signal while reducing power
consumption to a minimum.
The ST25R3920B is designed to operate from a wide power supply range (2.6 to 5.5 V from
-40 °C to +105 °C, 2.4 to 5.5 V from -20 °C to +105 °C), and a wide peripheral IO voltage
range (from 1.65 to 5.5 V).
Due to this combination of high RF output power, low power modes, wide supply range and
AEC-Q100 grade 2 qualification the device is perfectly suited for automotive applications.
– NFC-F / FeliCa™ up to 424 kbit/s
– NFC-V / ISO15693 up to 53 kb/s
– NFC-A / ISO14443A (106 kbit/s) and
NFC-F / FeliCa™ (212/424 kbit/s) card
emulation
– Active and passive peer to peer initiator
and target modes, up to 424 kbit/s
– Low level modes to implement MIFARE
Classic® compliant or other custom
protocols
• Key features
– Dynamic power output (DPO) controls the
field strength to stay within given limits
– Active wave shaping (AWS) reduces overand
under-shoots
– Noise suppression receiver (NSR) allows
reception in noisy environment
– Automatic antenna tuning (AAT) via
variable capacitor
– Integrated EMVCo® 3.1a compliant EMD
handling
– Automatic gain control and squelch feature
to maximize SNR
– Low power NFC active and passive target
modes
– Adjustable ASK modulation depth, from 0
to 82%
– Integrated regulators to boost system
PSRR
– AM/PM and I/Q demodulator with
baseband channel summation or automatic
channel selection
– Possibility to drive two independent single
ended antennas
– Measurement of antenna voltage amplitude
and phase, RSSI, on-chip supply and
regulated voltages
External communication interfaces
– 512-byte FIFO
– Serial peripheral interface (SPI) up to
5 Mbit/s
– I2C with up to 400 kbit/s in Fast-mode,
1 Mbit/s in Fast-mode Plus, and 3.4 Mbit/s
in High-speed mode
Electrical characteristics
– Wide supply voltage and ambient
temperature range (2.6 to 5.5 V from -40 °C
to +105 °C, 2.4 to 5.5 V from -20 °C to
+105 °C)
– Wide peripheral communication supply
range, from 1.65 to 5.5 V
– Quartz oscillator capable of operating with
27.12 MHz crystal with fast start-up