
Lucent Technologies Inc.
21
Data Sheet
October 1998
Relay, and Protector (SRP) for Long Loop and TR-57 Applications
L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring
Applications
(continued)
General
(continued)
Table 15. External Components Required
(continued)
1. Power is continuous RMS power.
2. R
1
/R
2
= 1, with a tolerance of 0.35% for 50 dB longitudinal balance, 0.2% for 58 dB longitudinal balance. Fuses F1 and F2 provide fail-safe
operation if excessive overvoltage conditions exist on Tip and Ring. They will not operate if the total power dissipation of the entire resistor
network is
≤
5 W at 85
°
C.
3. (R
3
+ R
6
)/(R
4
+ R
5
) = 1 with a tolerance of 0. 35% for 50 dB longitudinal balance, 0.2% for 58 dB longitudinal balance.
4. R
9
/R
1
= 100 with a tolerance of 0.5%.
5. Optional components to improve PSRR by 6 dB.
Comp.
C
CBN2
C
GBN
5
R
GBN
5
C
RT
R
RT
R
BIAS1
R
BIAS2
C
BIAS1
C
BIAS2
D
SPEED
Function
Implementation
External
External
External
External
External
External
External
External
External
External
Value
0.01
μ
F
47 pF
50 k
0.1
μ
F
1 M
19.6 k
19.6 k
10
μ
F
0.47
μ
F
20 V
Attribute
1
20%, 100 V
20%, 100 V
20%, 100 V
20%, 100 V
1%, 1/16 W
1%, 1/16 W
1%, 1/16 W
20%, 100 V
20%, 100 V
Zener
Battery Noise Cancellation
Battery Noise Cancellation
Battery Noise Cancellation
Ring Trip
Ring Trip
dc Bias for On-hook Trans.
dc Bias for On-hook Trans.
ac Transmission
ac Transmission
Reduce Settling Time Off-hook
to On-hook
dc Blocking
dc Blocking
ac Interface
ac Interface
ac Interface
ac Interface
ac Interface
ac Interface
ac Interface
ac Interface
C
B1
C
B2
R
T1
R
T2
R
GX
R
GX1
R
RV1
R
RV2
C
2
R
HB1
External
External
External
External
External
External
External
External
External
External
0.1
μ
F
0.1
μ
F
20%, 10 V
20%, 10 V
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
1%, 1/32 W
See ac Design Equations
See ac Design Equations
See ac Design Equations
See ac Design Equations
See ac Design Equations
See ac Design Equations
See ac Design Equations
See ac Design Equations