Data Sheet
January 2000
L7556, L7557 Low-Power SLICs
with Battery Switch
Electrical Characteristics (continued)
Table 9. Logic Inputs and Outputs
All outputs except RGDET and LBAT are open collectors with internal, 30 kΩ pull-up resistor. RGDET and LBAT are
open collectors without internal pull-up. Input pin B1 has a 40 kΩ pull-up; it goes low in the event of thermal shut-
down.
Parameter
Input Voltages:
Low Level (permissible range)
High Level (permissible range)
Input Currents:
Low Level (VCC = 5.25 V, VI = 0.4 V)
High Level (VCC = 5.25 V, VI = 2.4 V)
Output Voltages (open collector with internal pull-up resistor):
Low Level (VCC = 4.75 V, IOL = 360 µA)
High Level (VCC = 4.75 V, IOH = –20 µA)
Symbol
VIL
VIH
IIL
IIH
VOL
VOH
Min
–0.5
2.0
–75
–40
0
2.4
Typ Max
0.4
0.7
2.4
VCC
–115 –200
–60 –100
0.2
0.4
—
VCC
Unit
V
V
µA
µA
V
V
Ring Trip Requirements
s Ringing signal:
— Voltage, minimum 35 Vrms, maximum 100 Vrms.
— Frequency, 17 Hz to 23 Hz.
— Crest factor, 1.4 to 2.
s Ringing trip:
— ≤100 ms (typical), ≤250 ms (VBAT = –33 V, loop
length = 530 Ω).
s Pretrip:
— The circuits in Figure 3 will not cause ringing trip.
TIP
SWITCH CLOSES <12 ms
200 Ω
6 µF
TIP
10 kΩ
RING
RING
2 µF
100 Ω
TIP
RING
12-2572g (F)
Figure 3. Ring Trip Circuits
Lucent Technologies Inc.
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