CRX14

2/4

SUMMARY DESCRIPTION

The CRX14 is a contactless coupler, compliant

with the short range ISO14443B standard control-

led, 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 trans-

mission 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

The CRX14 targets short range applications which

need disposable or secure and re-usable prod-

ucts. The CRX14 includes an automated anti-col-

lision 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 STMi-

croelectronics probabilistic scanning methodolo-

gy. The CRX14 provides an anti-clone function

from FRANCE TELECOM which allows tag au-

thentication. With the use of the single chip cou-

pler CRX14, it is easy to design a reader with the

authentication capability and to build a system with

a high level of security at low cost.

Table 1. Signal Names

Figure 3. SO Connections

The CRX14 provides a complete analog interface,

compliant with the ISO/IEC 14443 recommenda-

tions for a radio-frequency power and signal inter-

face. It allows the ISO 14443-2 type B proximity

tag to be powered and to have control data trans-

mitted, via a simple antenna. The CRX14 is fabri-

cated with STMicroelectronics High Endurance

Single Polysilicon CMOS technology.

AI06828

RF OUT

CRX14

RF IN

Transmitter

Receiver

RAM

Buffer

I2C

Bus

Contr-

oller

OSC_SEL

OSC1

OSC2

PLL_RC

RESET

SCL

SDA

E0

E1

E2

GND

GND_RF

VCC

Vref

Antenna

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

1

AI06827

2

3

4

16

15

14

13

OSC_SEL

E1

OSC2

OSC1

RF IN

Vref

GND_RF

E0

CRX14

5

6

7

8

12

11

10

9

SDA

GND

SCL

RESET

E2

PL_RC

RF OUT

VCC