Lucent Technologies Inc.
3
Data Sheet
October 1998
Relay, and Protector (SRP) for Long Loop and TR-57 Applications
L8574D Resistive Subscriber Line Interface Circuit (SLIC), Ring
Table of Contents
(continued)
Tables
Page
Table 1. Pin Descriptions...........................................................................................................................................5
Table 2. Operating Conditions and Powering ............................................................................................................7
Table 3. Ring Trip Detector ........................................................................................................................................8
Table 4. Battery Feed ................................................................................................................................................8
Table 5. Electrical Characteristics of Pins PT, PR, and V
BF
Table 6. Loss of Power Supplies..............................................................................................................................10
Table 7. Analog Signal Pins.....................................................................................................................................11
Table 8. ac Transmission Characteristics.................................................................................................................13
Table 9. Logic Inputs (CE, CS, and B0—B3) and Output NSTAT............................................................................14
Table 10. Timing Requirements (B0—B3 and CS)..................................................................................................14
Table 11. Relay Driver (RDO)..................................................................................................................................14
Table 12. Battery Switch (SW1) and Ring Break Switch (SW2)..............................................................................15
Table 13. Ringing Access Switch (SW3) .................................................................................................................15
Table 14. Input State Coding...................................................................................................................................16
Table 15. External Components Required...............................................................................................................20
Table 16.
MMC
A31A8574AA and
MMC
A11A8574AA Module..............................................................................23
.......................................................................................9
Figures
Page
Figure 1. Architectural Diagram.................................................................................................................................4
Figure 2. Pin Layout ..................................................................................................................................................4
Figure 3. Switch On-State V-I Characteristics SW1 and SW2.................................................................................16
Figure 4. Switch On-State V-I Characteristics SW3.................................................................................................16
Figure 5. External Components Required...............................................................................................................19
Figure 6. Resistor Network......................................................................................................................................23
Figure 7. L8574 SLIC Matching Requirements .......................................................................................................24
Figure 8. Implementing the Noise Cancellation Function........................................................................................25
Figure 9. Ring Trip Threshold ..................................................................................................................................26
Figure 10. Loop Current vs. Loop Voltage...............................................................................................................28
Figure 11. Equivalent Complex Terminations..........................................................................................................29
Figure 12. Initial ac Interface for Complex Termination Between L8574 SLIC and T7504 Codec ..........................30
Figure 13. Revised ac Interface C
T
and C
R
Combined into a Single Capacitor C
Figure 14. Addition of Resistor R
SC
from XMT to IRP.............................................................................................31
Figure 15. TR-57 Application Diagram ....................................................................................................................33
S
.................................................31