CR14 STMicroelectronics, CR14 Datasheet - Page 10

• Manufacturer Part Number: CR14
• Description: Low Cost Iso14443 Type-b Contactless Coupler Chip With Anti-collision And Crc Management
• Manufacturer: STMicroelectronics

2 Signal description
2.6
2.7
2.8
Figure 4.
10/46
V
CC
E0
OPT
R1
0R
R2
E1
OPT
R3
0R
R4
Serial Data (SDA)
The SDA signal is bi-directional. It is used to transfer I²C data in and out of the CR14. It is an
open drain output that may be wire-OR’ed with other open drain or open collector signals on the
bus. A pull-up resistor must be connected from Serial data (SDA) to V
how the value of the pull-up resistor can be calculated).
Chip Enable (E0, E1, E2)
The Chip Enable inputs E0, E1, E2 are used to set and reset the value on the three least
significant bits (b3, b2, b1) of the 7-bit I²C Device Select Code. They are used for hardwired
addressing, allowing up to eight CR14 devices to be addressed on the same I²C bus. These
inputs may be driven dynamically or tied to V
(note that the V
When left open, E0, E1 and E2 are internally read at the logic level 0 due to the internal pull-
down resistors connected to each inputs.
Power Supply (V
Power is supplied to the CR14 using the V
V
The GND and GND_RF pins are ground connections. They must be connected together.
Decoupling capacitors should be connected between the V
Ground pin and the GND_REF Ground pin to filter the power line, as shown in
CC
CR14 Application Schematic
OPT
R5
0R
R6
E2
is the Power Supply pin that supplies the power (+5V) for all CR14 operations.
C3
22nF50V
WURTH 742-792-042
FL7
IL
1
2
3
4
5
6
7
8
and V
4
3
2
1
U1
CR14
J1
V
RF
E0
E1
E2
GND_RF
GND
GND
REF
IN
GND_RF
RF
IH
FL5 0R
FL4
FL6
OSC1
OSC2
GND
V
OUT
SDA
SCL
CC
CC
levels for the inputs are CMOS compatible, not TTL compatible).
0R
0R
C6
100nF50V
, GND, GND_RF)
16
15
14
13
12
11
10
9
V
CC
SDA
SCL
V
CC
+ C4
22uF 10V
C2 7pF50V
CC
C1 7pF50V
X1
13.56MHz
CC
, GND and GND_RF pins.
or GND to establish the Device Select Code
C8'
C8
8pF50V
100pF50V
C7
120pF50V
CC
Supply Voltage pin, the GND
C7'
33pF50V
C5
10pF50V
CC
D1
1N4148 (OPTIONAL)
R7
0R
.
R8
0R
(Figure 5
ANT2
ANT1
Figure
indicates
4.
AI12061
CR14