L8575
Dual-Resistive, Low-Cost SLIC
Advance Data Sheet
March 1997
10
Lucent Technologies Inc.
Electrical Characteristics
(continued)
Table 3. Battery Feed, Switchhook Detectors (LCA and LCB), and Fault Detectors (FLTA and FLTB)
1. Assumes 2 x 300
external dc feed resistors.
2. Detector values are independent of office battery and are valid over the entire range of V
BAT
.
3. Fault voltage is defined as the absolute value of the dc voltage across either dc feed resistor. If the voltage across either feed resistor
exceeds this value, a fault is determined to be present. FLT is forced to a 0 when D2 = 1 (ringing state).
Table 4. Ring-Trip Detectors (RTA, RTB, RZA, and RZB)
1. The ringing source consists of the ac and dc voltages added together (battery-backed ringing); the ringing return is ground.
2. RT must also indicate ring-trip when the ac ringing voltage is absent (<5 Vrms) from the ringing source.
3. Pretrip: Ringing must not be tripped by a 10 k
resistor in parallel with an 8
μ
F capacitor applied across Tip and Ring.
Parameter
Min
Typ
Max
Unit
Loop Resistance Range
1
:
(3.17 dBm overload into 600
)
I
LOOP
= 18 mA at V
BAT
= –48 V
Longitudinal Current Capability per Wire
Switchhook Detector Loop Resistance
2
:
Off-hook (LC = 1)
On-hook (LC = 0)
Fault Detector
2, 3
:
|
V
TIP
|
or
|
V
RING
– V
BAT
|
No Fault (FLT = 0)
Fault (FLT = 1)
Detection Delay t
DET
(no fault to fault; CFLT = 0.1
μ
F)
Release Delay (fault to no fault; CFLT = 0.1
μ
F)
1800
8.5
—
—
4800
—
—
—
—
—
mArms
4000
—
—
3200
—
—
39
10
1.6 t
DET
36
36
—
—
33
—
30
2.5 t
DET
V
V
ms
ms
Parameter
Min
Typ
Max
Unit
Ringing Source
1
:
Frequency (
)
dc Voltage
ac Voltage
Ring Trip
2, 3
(RT = 1):
Loop Resistance
Trip Time (
= 20 Hz)
RT Valid
Ringing Source Zero Crossing (referenced to V
BAT
/2):
Ringing Voltage Positive (RZ = 1)
Ringing Voltage Negative (RZ = 0)
19
–39.5
60
20
—
—
28
–57
105
Hz
V
Vrms
2000
—
—
—
—
—
—
200
80
ms
ms
3V
BAT
/4
—
—
—
—
V
BAT
/4
V
V