LUCL8574DP-D AGERE [Agere Systems], LUCL8574DP-D Datasheet - Page 32

• Manufacturer Part Number: LUCL8574DP-D
• Description: L8574D Resistive Subscriber Line Interface Circuit(SLIC), Ring Relay,and Protector(SRP)for Long Loop and TR-57 Applications
• Manufacturer: AGERE [Agere Systems]

L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring
Relay, and Protector (SRP) for Long Loop and TR-57 Applications
ac Design
Design Equations
As a practical design example, design the interface for
the following set of requirements:
RX = 0 dB
TX = 0 dB
ZT = 900
Hy = 900
First, calculate the gain constants:
Ko =
K
K
Second, calculate individual components:
R
Choose a standard value component:
R
R
C
Choose R
32
32
-------------------------------------- -
100 k
RCV
TX
------------------------------- -
R
RV1
RV1
RV2
R
-------------------------------------- -
100 k
GX1
=
100 k
=
R
100 k
= 73,487
= 73.2 k
=
= K
K
--------------------- -
GX1
------- -
Ko
---------- -
600
1
+
RCV
100 R
---------------------- -
Z
100
+
O
R
R
T
+
GX1
10
R
10
RCV
T1
C
R
=
T1
RX/20
TX/20
T1
=
X
= 100 k :
=
(continued)
=
900
---------- -
600
R
--------------
=
= 0
100
73.2 k
---------------------- -
RV1
= 1.2247 x 10
= 0.8165
1.01
100
= 1.2247
---------- -
400
1
(continued)
–
---------- -
400
1
-------- -
R
1
1
–
0/20
---------- -
900
1
= 1.2247
R
C
C
R
R
R
R
Choose a standard value resistor:
R
R
R
Therefore, for this design example, use the following
values in the circuit shown in Figure 12.
R
R
R
R
R
R
R
C
C
Figure 15 is the application circuit with the above
values.
T1
T2
T1
T2
T
T
GX
GX
GX
GX
HB
HB
GX
GX1
RV1
RV2
HB1
T
R
=
=
=
=
= 0
=
= 0 k
= 0
=
=
= 2 x K
= 2 x 0.8165 (100 k + 0)
= 163.3 k
= 165 k
= 165 k
= 73.2 k
= 0
= 165 k
= 100 k
---------- -
100
R
--------------- -
C
----------------------------------------- - 165 k
0.8165 1.2247
---------------------------- -
K
C
2
TX
T
C
1
R
165
TX
+
GX
= 0
K
R
-------------- -
(R
R
RCV
GX1
k
T1
GX1
1
+ R
+
=
100 R
---------------------- -
T1
R
)
RV1
1
Lucent Technologies Inc.
October 1998
Data Sheet