LUCL8576BP-D AGERE [Agere Systems], LUCL8576BP-D Datasheet - Page 20

• Manufacturer Part Number: LUCL8576BP-D
• Description: Dual Ringing SLIC
• Manufacturer: AGERE [Agere Systems]

L8576B Dual Ringing SLIC
Applications
ac Design
Example 1, Real Termination
The following design equations refer to the circuit in
Figure 20. Use these to synthesize real termination
impedance.
Termination impedance:
Receive gain:
20
20
V
S
Z
G
T/R
Z
Z
RC V
T
t
=
+
–
I
R
V
(continued)
T/R
R
=
--------- -
–
T/R
P
V
P
I
G
Z
T/R
T/R
------------------------------------------------------------------
PR
PT
t
1
R C V
(continued)
=
+
R
-----------
2R
R
=
1/2 L8576
R CV
T 1
P
---------- -
V
SLIC
V
+
F R O
T/R
+
Figure 20. ac Equivalent Circuit Using a T8503 Codec
---------------------------------- -
1
CURRENT
R
----------- -
R
SENSE
+
12
R C V
G P
-------- -
R
R
1500
G P
T 1
+
1
----------- -
R
+
R
R C V
A
A
-------- -
Z
T 1
V
Z
V
T/R
= –1
= 1
t
–
+
+
–
AX
125 V/A
A
V
= 6
Transmit gain:
Hybrid balance:
To optimize the hybrid balance, the sum of the currents
at the VF
to 0. The following expressions assume the hybrid bal-
ance network is the same as the termination imped-
ance:
VITR
+
–
TG
h
ba l
RCVN
RCVP
X
=
R
IN input of the codec op amp should be set
GX
R
20
GP
log
R
h
H B
R
R
R
bal
T1
G
RCV
T2
-------- -
R
R
R
=
TX
G
H B
HB
=
X
------------------------- -
G
TX
=
20
–
RC V
----------
R
=
G
R
log
R
T2
X
R C V
V
-------------- -
V
X
GSX
T/R
G
V
---------- -
VF
V
VF
-----------
Z
125
T X
G SX
T/R
T/R
X
R
G
IN
1/2 T8503 CODEC
O
Agere Systems Inc.
TX
–
+
RX
+2.4 V
May 2001
12-2554.o (F)
GSX