LUCL9310AP-D AGERE [Agere Systems], LUCL9310AP-D Datasheet - Page 50

• Manufacturer Part Number: LUCL9310AP-D
• Description: Line Interface and Line Access Circuit Full-Feature SLIC,Ringing Relay,and Test Access Device
• Manufacturer: AGERE [Agere Systems]

Full-Feature SLIC, Ringing Relay, and Test Access Device
ac Applications
First-Generation Codec ac Interface Net-
work: Complex Termination
The following reference circuit shows the complete
SLIC schematic for interface to the Agere T7504 first-
generation codec for the German complex termination
impedance. For this example, the ac interface was
designed for a 220
mination and hybrid balance with transmit gain and
receive gain set to 0 dBm. For illustration purposes,
2.2 Vrms PPM injection was assumed in this example.
This implies the overhead voltage is increased to 9.2 V
and hybrid meter pulse rejection is used. Also, this
example illustrates the device using the battery switch
with multiple battery operation and fixed overhead, cur-
rent limit, and loop closure threshold.
Complex Termination Impedance Design
Complex termination is specified in the form:
To work with this application, convert termination to the
form:
where:
R
R
C´ =
50
1
2
´ = R
´ =
R
-------
R
---------------------
R
1
1
2
1
R
+ R
+
(R
2
R
1
2
2
+ R
2
C
2
)
R
1
+ (820
(continued)
R
2
R
´
1
R
´
C
C´
2
|| 115 nF) complex ter-
5-6396(F)
5-6398(F)
ac Interface Using First-Generation Codec
R
shaping to get good gain flatness. These components
are a scaled version of the specified complex termina-
tion impedance.
Note that for pure (600
ponents R
used and is still 6.34 k .
R
(for complex and resistive terminations) R
varied to give specified transmit gain.
R
tions, the ratio of these resistors set the receive gain.
For resistive terminations, the ratio of these resistors
sets the return loss characteristic. For complex termi-
nations, the ratio of these resistors set the low-fre-
quency return loss characteristic.
C
nents provide high-frequency compensation to the
return loss characteristic.
For resistive terminations, these components are not
used and RCVN is connected to ground via a resistor.
R
Set Z
Z
Z
R
R
300 V/A.
R
At dc, C
R
where M is the scale factor.
M =
It can be shown:
R
and
C
TG
T/R
TGP
X
T3
N
HB
1
TGP
TGP
TGP
TGS
TGS
´ || R
/R
/R
/R
: sets hybrid balance for all terminations.
= R
(the specified termination resistance), in the
/R
T6
6340
--------------
N1
must be 6.34 k
= 6.34 k
= M x R
= M x R
TG
=
RCV
R
: with other components set, the transmit gain
/R
TGS
2
1
—Gain Shaping
TGP
GS
´ + C´ form.
/R
C
------
N2
M
TGS
/C
and C´ are open.
GP
: for complex terminations, these compo-
|| R
GS
1
2
: for both complex and resistive termina-
and C
´
´
TGS
(Z
TG
+ C
): these components give gain
GS
to set SLIC transconductance to
GS
are not used. Resistor R
, which is a scaled version of
) resistive terminations, com-
Agere Systems Inc.
X
July 2001
and R
TGP
T6
are
is