CRX14_05 Datasheet, PDF(5/40 Page) STMicroelectronics – Low Cost ISO14443 type-B Contactless Coupler Chip with Anti-Collision, CRC Management and Anti-Clone Function

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CRX14_05 Datasheet, PDF (5/40 Pages) STMicroelectronics – Low Cost ISO14443 type-B Contactless Coupler Chip with Anti-Collision, CRC Management and Anti-Clone Function

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CRX14

SUMMARY DESCRIPTION

The CRX14 is a contactless coupler that is compli-

ant with the short range ISO14443 type-B stan-

dard. It is controlled using the two wire IÂ²C bus.

The CRX14 generates a 13.56MHz signal on an

external antenna. Transmitted data are modulated

using Amplitude Shift Keying (ASK). Received

data are demodulated from the PICC (Proximity in-

tegrated Coupling Card) load variation signal, in-

duced 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 recep-

tion modes.

The CRX14 follows the ISO14443 type-B recom-

mendation for Radio frequency power and signal

interface.

The CRX14 is specifically designed for short range

applications that need disposable, or secure and

re-usable, 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 ca-

pability 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 tech-

nology.

The CRX14 is organized as 4 different blocks (see

Figure 3.):

â The IÂ²C bus controller. It handles the serial

connection with the application host. It is

compliant with the 400kHz IÂ²C bus

specification, and controls the read/write

access to all the CRX14 registers.

â 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.

â 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.

â 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 digi-

tal host (Microcontroller or ASIC). This host has to

manage the entire communication protocol in both

transmit and receive modes, through the IÂ²C serial

bus.

Figure 2. Logic Diagram

VCC VREF

OSC1

SCL

SDA

CRX14

RFOUT

OSC2

Antenna

RFIN

GND

GND_RF

AI06828B

Table 1. Signal Names

RFOUT

Antenna Output Driver

RFIN

Antenna Input Filter

OSC1

Oscillator Input

OSC2

Oscillator Output

E0, E1, E2

Chip Enable Inputs

SDA

IÂ²C Bi-Directional Data

SCL

IÂ²C Clock

VCC

Power Supply

GND

Ground

VREF

Transmitter Reference Voltage

GND_RF

Ground for RF circuitry

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