Data Sheet
January 2000
L7556, L7557 Low-Power SLICs
with Battery Switch
Recommended Operating Conditions
Parameter
Ambient Temperature
V
CC
Supply Voltage
V
BAT1
Supply Voltage
V
BAT2
Supply Voltage
Loop Closure Threshold-detection Programming Range
dc Loop Current-limit Programming Range
On- and Off-hook 2-wire Signal Level
ac Termination Impedance Programming Range
Min
–40
4.75
–24
–16
—
5
—
150
Typ
—
5.0
–48
–28
10
22
1
600
Max
85
5.25
–60
V
BAT1
I
LIM
45
2.2
1300
Unit
°C
V
V
V
mA
mA
Vrms
Ω
Electrical Characteristics
Minimum and maximum values are testing requirements. Typical values are characteristic of the device and are
the result of engineering evaluations. Typical values are for information purposes only and are not part of the test-
ing requirements. Minimum and maximum values apply across the entire temperature range (–40 °C to +85 °C)
and the entire battery range unless otherwise specified. Typical is defined as 25 °C, V
CC
= 5.0 V, V
BAT1
= –48 V,
V
BAT2
= –48 V, and I
LIM
= 40 mA. Positive currents flow into the device. Test circuit is Figure 4 unless noted.
Table 4. Power Supply
Parameter
Power Supply—Powerup, No Loop Current:
I
CC
I
BAT
(V
BAT
= –48 V)
Power Dissipation (V
BAT
= –48 V)
Power Supply Rejection 500 Hz to 3 kHz (See Figures 5, 6, 15, and 16.)
1
:
V
CC
V
BAT
Thermal Protection Shutdown (T
jc
)
Thermal Resistance, Junction to Ambient (θ
JA
)
Min
—
—
—
35
45
—
—
Typ
2.8
–2.3
125
—
—
175
60
Max
—
—
155
—
—
—
—
Unit
mA
mA
mW
dB
dB
°C
°C/W
1. This parameter is not tested in production. It is guaranteed by design and device characterization.
Lucent Technologies Inc.
7
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