
Data Sheet
July 2001
Full-Feature SLIC, Ringing Relay, and Test Access Device
L9310 Line Interface and Line Access Circuit
Agere Systems Inc.
11
Pin Information
(continued)
Table 1. Pin Descriptions
Pin
1
Symbol
LCTH
Type
I
Name/Function
Loop Closure Program Input.
Connect a voltage source or ground, via a resistor,
to this point to program the loop closure threshold.
SLIC Internal Reference Voltage.
Output of internal 2.35 V SLIC reference volt-
age.
Overhead Voltage Program Input.
Connect a voltage source to this point to pro-
gram the overhead voltage. Voltage source may be external or derived via a resistor
divider from V
REF
. A programmable external voltage source may be used to provide
software control of the overhead voltage. If a resistor or voltage source is not con-
nected, the overhead voltage will default to approximately 5.5 V (sufficient to pass
3.14 dBm in to 900
). If the default overhead is desired, connect this pin to ground.
Current-Limit Program Input.
Connect a voltage source to this point to program
the dc current limit. Voltage source may be external or derived via a resistor divider
from V
REF
. A programmable external voltage source may be used to provide soft-
ware control of the loop closure threshold.
Filter Capacitor.
Connect a 0.1
μ
F capacitor from this node to ground for filtering.
Filter Capacitor.
Connect a capacitor from this node to OVH to control the rate of
change of the overhead voltage. If controlled overhead is not desired, leave this
node open.
Polarity Reversal Slowdown Capacitor.
Connect a capacitor from this node to
ground to control the rate of battery reversal. If controlled battery reversal is not
desired, leave pin is open.
Polarity Reversal Slowdown Capacitor.
Connect a capacitor from this node to
ground to control the rate of battery reversal. If controlled battery reversal is not
desired, leave pin is open.
Loop Closure Filter Capacitor.
PPM injection can cause false loop closure indica-
tion. Connect a capacitor from this node to V
CC
to filter the loop closure detector. If
loop closure filtering is not required, leave this node open.
Battery Ground.
Ground return for the battery supply.
Auxiliary Battery.
If a lower-voltage auxiliary battery is used, connect the auxiliary
battery supply to this node. If a power control resistor is used, connect the power
control resistor from this node to V
BAT1
. If no power control technique is used, con-
nect this node to V
BAT1
.
Office Battery Supply.
Negative high-voltage power supply.
Office Battery Supply.
Negative high-voltage power supply.
Battery Ground.
Ground return for the battery supply.
Test Input.
This input injects a test signal to the line when an appropriate test oper-
ational state is chosen. Connect this node to V
REF
if not used.
Receive PPM Signal Input.
This high-impedance input controls the PPM differen-
tial voltage on tip and ring. The PPM signal may be present at this pin at all times;
however, PPM will only be transmitted to tip and ring if the appropriate active-PPM
state is chosen. ac couple PPM signal to this node. Connect this node to V
REF
if not
used.
2
V
REF
O
3
OVH
I
4
V
PROG
I
5
6
CF2
CF1
—
—
7
FB2
—
8
FB1
—
9
LCF
—
10
11
BGND
RPWR
G
P
12
13
14
15
V
BAT1
V
BAT1
BGND
TESTSIG
P
P
G
I
16
PPMIN
I