CS61574-IL Cirrus Logic, Inc., CS61574-IL Datasheet - Page 26

• Manufacturer Part Number: CS61574-IL
• Description: Interface, T1/E1 Line Interface
• Manufacturer: Cirrus Logic, Inc.

APPLICATIONS
Line Interface
Figures A1-A3 show typical T1 and E1 line inter-
face application circuits. Table A1 shows the
external components which are specific to each
application. Figure A1 illustrates a T1 interface in
the Host Mode. Figure A2 illustrates a 120
interface in the Hardware Mode. Figure A3 illus-
trates a 75
Hardware Mode.
26
E1 interface in the Extended
Frequency
1.544 (T1)
2.048 (E1)
Encoder/
Decoder
Monitor
Control
Format
Frame
MHz
&
XTL
RV+
+
28
12
11
10
CXT6176
CXT8192
1
5
7
6
8
3
4
2
9
Crystal
68 F
RGND
XTL
CLKE
ACLKI
LOS
DPM
MODE
RPOS
RNEG
RCLK
TPOS
TNEG
TCLK
XTALIN
XTALOUT
Figure A1. T1 Host Mode Configuration
Table A1. External Component Values
0.1 F
RGND
CS61577
+5V
RV+
Cable
MODE
HOST
100
120
75
21
IN
22
E1
TV+
TGND
15
14
0/1/1 - 1/1/1
LEN2/1/0
MRING
RRING
TRING
The 1:2 receiver transformer has a grounded cen-
ter tap on the IC side. Resistors R1 and R2
between the RTIP and RRING pins to ground
provide the termination for the receive line. The
transmitter also uses a 1:2 transformer. A 0.47 F
capacitor is required in series with the transmit
transformer primary. This capacitor is needed to
prevent any output stage imbalance from resulting
in a DC current through the transformer primary.
This current might saturate the transformer pro-
ducing an output offset level shift.
SCLK
MTIP
RTIP
+
SDO
TTIP
0/0/0
0/0/0
0/0/1
SDI
INT
CS
1.0 F
TGND
27
26
23
24
25
19
20
17
18
16
13
+5V
not used
not used
not used
0.47 F
100 k
R1
R2
4.4
R3
Serial
Port
1
3
5
2
6
PE-65351
PE-65351
P
2CT:1
1:2CT
R1 and R2
2
6
1
5
200
240
150
RECEIVE
LINE
TRANSMIT
LINE
CS61577
DS155PP2