CRX14 Datasheet, PDF (2/4 Pages) STMicroelectronics – Low Cost 13.56MHz / I²C Short Range Contactless Coupler Chip with anti-collision, CRC management and anti-clone function

CRX14
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
CRX14
VCC
Vref
OSC_SEL
OSC1
OSC2
PLL_RC
RESET
SCL
SDA
E0
E1
E2
Transmitter
I2C
Bus RAM
Contr- Buffer
oller
Receiver
RF OUT
Antenna
RF IN
GND
GND_RF
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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
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
Figure 3. SO Connections
CRX14
Vref
RF IN
E0
E1
E2
RESET
PL_RC
GND
1
16 VCC
2
15 RF OUT
3
14 GND_RF
4
13 OSC1
5
12 OSC2
6
11 OSC_SEL
7
10 SCL
8
9 SDA
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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.
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