
6
Lucent Technologies Inc.
Data Sheet
March 1997
L8551 Low-Power SLIC
Functional Description
Table 2. Input State Coding
Table 3. Supervision Coding
Absolute Maximum Ratings
(@ T
A
= 25
°
C)
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess
of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for extended
periods can adversely affect device reliability.
Note: The IC can be damaged unless all ground connections are applied before, and removed after, all other connections. Furthermore, when
powering the device, the user must guarantee that no external potential creates a voltage on any pin of the device that exceeds the device
ratings. Some of the known examples of conditions that cause such potentials during powerup are the following: 1) an inductor connected
to Tip and Ring can force an overvoltage on V
BAT
through the protection devices if the V
BAT
connection chatters, and
2) inductance in the V
BAT
lead could resonate with the V
BAT
filter capacitor to cause a destructive overvoltage.
B0
1
B1
1
State/Definition
Powerup, Forward Battery.
Normal talk and battery feed state. Pin PT is positive with respect to PR.
On-hook transmission is enabled.
2-Wire Wink.
Pins PT and PR are put at the same potential (near ground).
Disconnect.
The Tip and Ring amplifiers are turned off, and the SLIC goes to a high-impedance state
(>100 k
).
Low-Power Scan.
Except for off-hook suppression, all circuits are shut down to conserve power. Pin
PT is positive with respect to pin PR. On-hook transmission is disabled.
1
0
0
0
0
1
Pin NLC
Pin NRDET
Pin RGDET
0 = off-hook
1 = on-hook
0 = ring trip
1 = no ring trip
1 = ring ground
0 = no ring ground
Parameter
Symbol
V
CC
V
BAT
—
—
T
J
T
stg
R
H
—
V
PT
, V
PR
V
PT
, V
PR
I
RTSP
, I
RTSN
Value
7.0
–63
Unit
V
V
V
V
°
C
°
C
%
V
V
V
μ
A
5 V Power Supply
Battery (Talking) Supply
Logic Input Voltage
Analog Input Voltage
Maximum Junction Temperature
Storage Temperature Range
Relative Humidity Range
Ground Potential Difference (BGND to AGND)
PT or PR Fault Voltage (dc)
PT or PR Fault Voltage (10 x 1000
μ
s)
Current into Ring Trip Inputs
–0.5 to +7.0
–7.0 to +7.0
165
–40 to +125
5 to 95
±
3
(V
BAT
– 5) to +3
(V
BAT
– 15) to +15
±
240