CRX14_10 Datasheet, PDF (6/47 Pages) STMicroelectronics – ISO14443 type-B contactless coupler chip with anti-collision, CRC management and anti-clone function

Summary description
1
Summary description
CRX14
The CRX14 is a contactless coupler that is compliant with the short range ISO14443 type-B
standard. It is controlled using the two wire I²C bus.
The CRX14 generates a 13.56 MHz signal on an external antenna. Transmitted data are
modulated using Amplitude Shift Keying (ASK). Received data are demodulated from the
PICC (Proximity integrated Coupling Card) load variation signal, induced on the antenna,
using Bit Phase Shift Keying (BPSK) of a 847kHz sub-carrier. The Transmitted ASK wave is
10% modulated. The Data transfer rate between the CRX14 and the PICC is 106 Kbit/s in
both transmission and reception modes.
The CRX14 follows the ISO14443 type-B recommendation for Radio frequency power and
signal interface.
The CRX14 is specifically designed for short range applications that need disposable or
secure and reusable, products.
The CRX14 includes an automated anti-collision mechanism that allows it to detect and
select any ST short range memories that are present at the same time within its range. The
anti-collision mechanism is based on the STMicroelectronics probabilistic scanning method.
The CRX14 provides an anti-clone function, from FRANCE TELECOM, which allows the
authentication of the ST short range memories. Using the CRX14 single chip coupler,
therefore, it is easy to design a reader, with authentication capability and to build an end
application with a high level of security at low cost.
The CRX14 provides a complete analog interface, compliant with the ISO14443 type-B
recommendations for Radio-Frequency power and signal interfacing. With it, any ISO14443
type-B PICC products can be powered and have their data transmission controlled via a
simple antenna.
The CRX14 is fabricated in STMicroelectronics High Endurance Single Poly-silicon CMOS
technology.
The CRX14 is organized as 4 different blocks (see Figure 2):
● The I²C bus controller. It handles the serial connection with the application host. It is
compliant with the 400kHz I²C bus specification, and controls the read/write access to
all the CRX14 registers.
● The RAM buffer. It is bi-directional. . It stores all the request frame Bytes to be
transmitted to the PICC, and all the received Bytes sent by the PICC on the answer
frame.
● The transmitter. It powers the PICCs by generating a 13.56MHz signal on an external
antenna. The resulting field is 10% modulated using ASK (amplitude shift keying) for
outgoing data.
● The receiver. It demodulates the signal generated on the antenna by the load variation
of the PICC. The resulting signal is decoded by a 847kHz BPSK (binary phase shift
keying) sub-carrier decoder.
The CRX14 is designed to be connected to a digital host (Microcontroller or ASIC). This
host has to manage the entire communication protocol in both transmit and receive modes,
through the I²C serial bus.
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Doc ID 8880 Rev 4