ST25R3909 Datasheet, PDF (1/3 Pages) STMicroelectronics – AM/PM demodulator

ST25R3909
ISO-14443 A/B, 13.56 MHz mid-range reader
QFN32
Features
• Close loop adjustment of ASK modulation for
accurate control of modulation depth in case of
ISO-14443 B protocol
• Low power (3.5 μA) NFC target mode
• AM/PM demodulator
• Accurate RF envelope measurement (8-bit A/D
converter)
• High output power at 3.3 V power supply:
– Up to 700 mW in case regulator is
externally shorted
– Up to 500 mW in case of differential output
when antenna trimming is used
– Up to 125 mW in case of single ended
output when antenna trimming is used
• Squelch for gain reduction, to compensate for
noise generated by transponder processing
• Transparent mode
• Amplitude and phase measurement
• Supporting 13.56 MHz and 27.12 MHz quartz
oscillators with fast start-up
• Supply voltage range from 2.4 to 3.6 V
• Wide temperature range: -40 ºC to 85 ºC
• Package: 32-pin QFN32, 5 mm x 5 mm
Data brief - not recommended for new design
Description
The ST25R3909 is a high performance
13.56 MHz RFID reader, with two differential, low
impedance (1.5 Ohm) antenna drivers.
These drivers are unmatched, allowing the
ST25R3909 to deliver up to eight times the output
power of a standard HF reader IC using the same
power supply voltage, and reducing in half the
power consumption at the same output power.
The ST25R3909 can operate already at 2.4 V,
with a low power operating mode of 5 mA, making
it perfectly suited for portable or battery-powered
applications.
For applications where high power is required the
ST25R3909 can deliver up to 700 mW, thus
avoiding the need for complex external booster
circuitry.
The component count and complexity of the
design is further reduced through automatic
modulation depth adjustment.
The analog front end (AFE) is complemented by a
highly integrated data framing engine for both
ISO-14443 A and B. This includes data rates up
to 848 kbit/s, with all framing and synchronization
tasks on board, and enables to build a complete
HF RFID reader using only a low end
microcontroller.
The ST25R3909 supports reader to tag and Peer
to Peer communication using the NFCIP-1 active
communication mode with a 106 kbps data rate.
Other standard and custom protocols, such as
ISO-15693 or FeliCa^™ can be implemented via
transparent mode. The ST25R3909 features a
SPI, which enables bi-directional communication
with the external microcontroller.
November 2016
DocID029999 Rev 1
This is information on a product still in production but not recommended for new designs. For further information contact
your local STMicroelectronics sales office.
1/3
www.st.com