STMICROELECTRONICS CRX14

CRX14
Low Cost 13.56MHz / I²C Short Range Contactless Coupler Chip
with anti-collision, CRC management and anti-clone function
DATA BRIEFING
FEATURES SUMMARY
■ Single 5V ±500mV Supply Voltage
■
SO16N package
■
External Oscillator
Figure 1. Packages
– 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
Function
Proprietary
16
1
SO16 (MQ)
150 mil width
Anti-Clone
– 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
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 antenna, using
Bit Phase Shift Keying (BPSK) coding of an
847kHz sub-carrier. The Transmitted ASK wave is
10% modulated. The Data transfer rate between
the CRX14 and the tag is 106Kbit/s in both 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
CRX14
VCC
Vref
OSC_SEL
OSC1
OSC2
PLL_RC
RESET
SCL
SDA
E0
E1
E2
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
Oscillator input
PLL_RC
PLL RC filter Input
Vref
Transmitter Reference Voltage
OSC_SEL
13.56MHz/32.768kHz osc select
RESET
Reset
SCL
I²C Clock
SDA
I²C Bi-Directional Data
E0
I²C Chip Enable
E1
I²C Chip Enable
E2
I²C Chip Enable
RF OUT
Transmitter
Figure 3. SO Connections
I2C
Bus
RAM
Contr- Buffer
Receiver
oller
Antenna
CRX14
RF IN
GND
GND_RF
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-collision is based on the STMicroelectronics probabilistic scanning methodology. The CRX14 provides an anti-clone function
from FRANCE TELECOM which allows tag authentication. With the use of the single chip coupler CRX14, it is easy to design a reader with the
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authentication capability and to build a system with
a high level of security at low cost.
Vref
RF IN
E0
E1
E2
RESET
PL_RC
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
RF OUT
GND_RF
OSC1
OSC2
OSC_SEL
SCL
SDA
AI06827
The CRX14 provides a complete analog interface,
compliant with the ISO/IEC 14443 recommendations 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.
CRX14
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 organized in four blocks:
– The I²C bus controller handles the serial connection with the application host. It is compliant
with the 400kHz I²C bus specification and it controls the read/write access to all the CRX14 registers.
The CRX14 is designed to be connected to a digital host (Microcontroller or ASIC) which has to
manage all the communication protocol in both
transmit and receive mode through the I²C serial
bus.
– 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 answer 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
00h
01h
02h
03h
Access
Purpose
W
Set parameter register
R
Read parameter register
W
Store and send request frame to the tag.
Store tag answer frame
R
Transfer register content to Host
W
Start the Authenticate process
R
Get the Authenticate status
W
Launch the automated anti-collision process
R
Not Applicable. Return data FFh.
Parameters register
Input/Output frame register
Authenticate register
Slot Marker register
PART NUMBERING
For a list of available options (speed, package,
etc.) or for further information on any aspect of this
device, please contact your nearest ST Sales Office.
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
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted
by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject
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 devices or systems without express written approval of STMicroelectronics.
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