SGS Thomson Microelectronics CRX14 Datasheet

CRX14

Low Cos t 13.5 6MHz / I²C Sh ort Range Conta ctle ss Coup ler Chip

with anti-collision, CRC management and anti-clone function

DATA BRIEFING

FEATURES SUMMARY

■ Single 5V ±500mV Supply Voltage

■ SO16N package

■ External Oscillator

– 13.56MHz Quartz
– 32.768kHz Quartz with Frequency Multiplier

■ Contactless Communication

– 13.56MHz Carrier Frequency
– ISO 14443B - 2 Air Interface Compliant
– ISO 14443B - 3 Frame Format Compliant
– Support Frame Answer with/without SOF/

EOF
– CRC generation and check
– France Telecom Proprietary Anti-Clone

Function
– Automated ST anti-collision exchange

■ I²C Communication

– Two Wire I²C Serial Interface
– Supports 400 kHz Protocol
– 3 Chip Enable pin
– Up to 8 CRX14 connected on the same bus

Figure 1. Packages

16

1

SO16 (MQ)

150 mil width

June 2002

Complete data available under NDA.

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CRX14

SUMMARY DESCRIPTION

The CRX14 is a contactless coupler, compliant
with the short range ISO14443B standard control­led, using the two wire I²C bus.

The CRX14 generates a 13.56MHz signal on an
external antenna. Transmitted data are modulated
using Amplitude Shift Keying (ASK) modulation.
Received data are demodulated from the tag load
variation signal, generated on the a ntenna, using
Bit Phase Shift Keying (BPSK) coding of an
847kHz sub-carrier. The Transmitted ASK wave is
10% modulated. The Data transfer rate bet ween
the CRX14 and t he t ag is 106Kbit/s in bot h trans­mission and reception modes.

The CRX14 follows the ISO 14443 part 2 type B
recommendation for the radio-frequency power
and signal interface.

Figure 2. Logic Diagram

authentication capability and to build a system with
a high level of security at low cost.

Table 1. Signal Names

RF OUT Antenna Output Driver
RF IN Antenna Input Filter
VCC / GND Power Supply & Ground
GND_RF Ground for RF circuitry
OSC1 /

OSC2
PLL_RC PLL RC filter Input
Vref Transmitter Reference Voltage
OSC_SEL 13.56MHz/32.768kHz osc select
RESET Reset
SCL I²C Clock

Oscillator input

OSC_SEL

OSC1
OSC2

PLL_RC

RESET

SCL

SDA

E0
E1
E2

CRX14

I2C

Bus

Contr-

oller

V

CC

RAM

Buffer

GND GND_RF

Vref

Transmitter

Receiver

RF OUT

Antenna

RF IN

AI06828

The CRX14 targets short range applications which
need disposable or secure and re-usable prod­ucts. The CRX14 includes an automated anti-col­lision mechanism that allows it to detect and select
tags present at the same time within range of the
CRX14 . The anti-collisio n is ba sed on t he STM i­croelectronics probabilistic scanning methodolo­gy. The CRX14 provides an anti-clone function
from FRANCE TELECOM which allows tag au­thentication. With the us e of the single chip cou­pler CRX14, it is easy to design a reader with the

SDA I²C Bi-Directional Data
E0 I²C Chip Enable
E1 I²C Chip Enable
E2 I²C Chip Enable

Figure 3. SO Connections

CRX14

Vref

RF IN

E1
E2

RESET

PL_RC

16

1
2
3
4
5
6
7
8

AI06827

15
14
13
12
11
10

9

V

CC

RF OUT
GND_RFE0
OSC1
OSC2
OSC_SEL
SCL
SDAGND

The CRX14 provides a complete analog interface,
compliant with the ISO/IEC 14443 recomm enda­tions for a radio-frequency power and signal inter­face. It allows the ISO 14443-2 type B proximity
tag to be powered and to have control data trans­mitted, via a simple antenna. The CRX14 is fabri­cated with STMicroelectronics High Endurance
Single Polysilicon CMOS technology.

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CRX14

The CRX14 is organized in four blocks:

– The I²C bus c ontroller handles the serial con-

nection with the application host. It is com pliant
with the 400kHz I²C bus specification and it con­trols the read/write access to all the CRX14 reg­isters.

– The RAM buffer is bi-directional. It stores all the

request frame bytes to be transmitted to the tag
and all received bytes send by the tag on the an-

on the antenna by the load variation of the con­tactless tag. The resulting signal is decoded by
a 847KHz BPSK (binary phase shift keying)
sub-carrier decoder.

The CRX14 is designed to be connec ted t o a dig­ital host (Microcontroller or ASIC) which has to
manage all the communication protocol in both
transmit and receive mode th rough the I²C serial
bus.

swer frame.

– The transmitter powers all the contactless tags,

within range, by generating a RF magnetic field
at 13.56MHz on an external antenna. The field
is 10% modulated using ASK (amplitude shift
keying) modulation for outgoing data.

CRX14 DEVICE OPERATION

The CRX14 chip coupler provides four volatile reg­isters. They control all the behaviour of the device
and are described in Table 2.

– The receiver demodulates the signal generated

Table 2. CRX14 Control Registers

I2C Address Access Purpose

00h Parameters register

01h Input/Output frame register

W Set parameter register

R Read parameter register

Store and send request frame to the tag.

W

Store tag answer frame

R Transfer register content to Host

02h Authenticate register

03h Slot Marker register

PART NUMBERING

For a list of available options (speed, package,

W Start the Authenticate process

R Get the Authenticate status

W Launch the automated anti-collision process

R Not Applicable. Return data FFh.

device, please contact your nearest ST Sales O f­fice.

etc.) or for further information on any aspect of this

Table 3. Ordering Information Scheme

Example: CRX14 –MQ/XX

Device Type

CRX14

Package

MQ = SO16 (150 mil width)

Customer Code

XX = Given by the issuer

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CRX14

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by implic ation or oth erwise under any patent or patent rights of STMicroelectron i cs . Specificat i ons mentioned in this publicati on are s ubject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devi ces or systems wi thout express written ap proval of STMi croelectronics.

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