For further information contact your local STMicroelectronics sales office.

June 2019

DB3075 Rev 2

1/3

ST25R3914

ST25R3915

Automotive high performance HF reader / NFC initiator

with 1 W output power supporting AAT

Data brief

Features

• AEC-Q100 qualified

• ISO 18092 (NFCIP-1) Active P2P

• ISO14443A, ISO14443B, ISO15693 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

• ST25R3914: VFQFPN32, 5 mm x 5 mm

package with wettable flanks

• ST25R3915: 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), ISO 15693 reader 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 (AAT)

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 Ω) 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.

QFN32 / VFQFPN32

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