ST25R3920B Automotive NFC reader for CCC digital key and car center console Datasheet - production data 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 VFQFPN32 to 82% (5 x 5 mm) Integrated regulators to boost system PSRR Features AM/PM and I/Q demodulator with baseband channel summation or automatic AEC-Q100 qualified channel selection Operating modes Possibility to drive two independent single Reader/writer ended antennas Card emulation Measurement of antenna voltage amplitude Active and passive peer to peer and phase, RSSI, on-chip supply and regulated voltages RF communication External communication interfaces EMVCo 3.1a analog and digital compliant 512-byte FIFO NFC-A / ISO14443A up to 848 kbit/s Serial peripheral interface (SPI) up to NFC-B / ISO14443B up to 848 kbit/s 5 Mbit/s NFC-F / FeliCa up to 424 kbit/s I2C with up to 400 kbit/s in Fast-mode, NFC-V / ISO15693 up to 53 kb/s 1 Mbit/s in Fast-mode Plus, and 3.4 Mbit/s NFC-A / ISO14443A (106 kbit/s) and in High-speed mode NFC-F / FeliCa (212/424 kbit/s) card Electrical characteristics emulation Wide supply voltage and ambient Active and passive peer to peer initiator temperature range (2.6 to 5.5 V from -40 C and target modes, up to 424 kbit/s to +105 C, 2.4 to 5.5 V from -20 C to Low level modes to implement MIFARE +105 C) Classic compliant or other custom Wide peripheral communication supply protocols range, from 1.65 to 5.5 V Key features Quartz oscillator capable of operating with Dynamic power output (DPO) controls the 27.12 MHz crystal with fast start-up field strength to stay within given limits Active wave shaping (AWS) reduces over- and under-shoots Noise suppression receiver (NSR) allows reception in noisy environment Automatic antenna tuning (AAT) via variable capacitor June 2022 DS13890 Rev 3 1/158 This is information on a product in full production. www.st.comContents ST25R3920B Contents 1 Applications . 11 2 Description 12 2.1 System diagram 13 2.2 Block diagram 15 2.2.1 Transmitter . 15 2.2.2 Receiver . 16 2.2.3 Phase and amplitude detector 16 2.2.4 Automatic antenna tuning (AAT) 16 2.2.5 A/D converter . 16 2.2.6 External field detector 16 2.2.7 Quartz crystal oscillator . 17 2.2.8 Power supply regulators 17 2.2.9 POR and bias 17 2.2.10 RC oscillator and Wake-up timer 17 2.2.11 TX encoding 17 2.2.12 RX decoding . 17 2.2.13 FIFO 18 2.2.14 Control logic 18 2.2.15 Host interface . 18 2.2.16 Passive target memory . 18 2.2.17 P2RAM . 18 3 Pin and signal description . 19 4 Application information . 21 4.1 Power-on sequence . 21 4.2 Operating modes . 21 4.2.1 Transmitter . 22 4.2.2 Receiver . 23 4.2.3 Antenna tuning 28 4.2.4 Wake-up mode 29 4.2.5 Quartz crystal oscillator . 30 4.2.6 Timers 30 2/158 DS13890 Rev 3