ST25R3914 Datasheet, PDF (1/3 Pages) STMicroelectronics – Capacitive sensing - Wake-up

ST25R3914
ST25R3915
Automotive high performance reader / NFC initiator
with 1 W output power
Data brief
QFN32
Features
• AEC-Q100 qualified
• ISO 18092 (NFCIP-1) Active P2P
• ISO14443A, ISO14443B and FeliCa™
• Support HBR up to 848 kbit/s PICC to PCD and
PCD to PICC framing
• Capacitive sensing - Wake-up
• Automatic antenna tuning system providing
tuning of antenna LC tank (ST25R3914 only)
• Automatic modulation index adjustment
• AM and PM (I/Q) demodulator channels with
automatic selection
• Up to 1 W in case of differential output
• User selectable and automatic gain control
• Transparent and Stream modes to implement
MIFARE™ Classic compliant or other custom
protocols
• Possibility of driving two antennas in single
ended mode
• Oscillator input capable of operating with 13.56
MHz or 27.12 MHz crystal with fast start-up
• 6 Mbit/s SPI with 96 bytes FIFO
• Wide supply voltage range from 2.4 V to 5.5 V
• Wide temperature range: -40 °C to 125 °C
• QFN32, 5 mm x 5 mm package
Description
The ST25R3914/5 are highly integrated NFC
Initiators / HF Reader ICs for automotive
applications, AEC-Q100 grade 1 qualified,
including the analog front end (AFE) and a highly
integrated data framing system for ISO 18092
(NFCIP-1) initiator, ISO 18092 (NFCIP-1) active
target, ISO 14443A and B reader (including high
bit rates) and FeliCa™ reader. Implementation of
other standard and custom protocols like
MIFARE™ Classic is possible using the AFE and
implementing framing in the external
microcontroller (Stream and Transparent modes).
The ST25R3914/5 are positioned perfectly for the
infrastructure side of the NFC system, where
users need optimal RF performance and flexibility
combined with low power.
Thanks to Automatic Antenna Tuning technology,
the devices are optimized for applications with
directly driven antennas. The ST25R3914/5 are
alone in the domain of HF reader ICs as they
contain two differential low impedance (1 Ohm)
antenna drivers.
The ST25R3914/5 include several features that
make them very suited for low power applications.
They contain a low power capacitive sensor that
can be used to detect the presence of a card
without switching on the reader field. The
presence of a card can also be detected by
performing a measurement of amplitude or phase
of signal on antenna LC tank, and comparing it to
the stored reference. They also contain a low
power RC oscillator and wake-up timer that can
be used to wake up the system after a defined
time period, and to check for the presence of a
tag using one or more low power detection
techniques (capacitive, phase or amplitude).
The ST25R3914/5 are designed to operate from a
wide (2.4 V to 5.5 V) power supply range;
peripheral interface IO pins support power supply
range from 1.65 V to 5.5 V.
October 2016
DocID029866 Rev 1
For further information contact your local STMicroelectronics sales office.
1/3
www.st.com