XRT59L921 Datasheet, PDF (3/32 Pages) Exar Corporation – TWENTY-ONE CHANNEL E1 LINE INTERFACE UNIT

REV. 1.2.1
XRT59L921
TWENTY-ONE CHANNEL E1 LINE INTERFACE UNIT
TABLE OF CONTENTS
GENERAL DESCRIPTION................................................................................................. 1
FEATURES ..................................................................................................................................................... 1
APPLICATIONS ............................................................................................................................................... 1
FIGURE 1. BLOCK DIAGRAM OF THE XRT59L921 ............................................................................................................................. 1
ORDERING INFORMATION .................................................................................................................... 2
FIGURE 2. PIN OUT OF THE XRT59L921 (BOTTOM VIEW).................................................................................................................. 2
TABLE OF CONTENTS ............................................................................................................ I
PIN DESCRIPTIONS ........................................................................................................................................ 3
RECEIVER ELECTRICAL CHARACTERISTICS ...................................................................................... 12
TRANSMITTER ELECTRICAL CHARACTERISTICS ............................................................................... 12
FIGURE 3. E1. ITU G.703 PULSE TEMPLATE FOR TRANSMITTER OUTPUT........................................................................................ 13
DC ELECTRICAL CHARACTERISTICS ................................................................................................... 13
AC ELECTRICAL CHARACTERISTICS.................................................................................................... 14
PER CHANNEL POWER CONSUMPTION INCLUDING THE LINE POWER DISSIPATION, TRANMISSION AND RECEIVE PATHS
ALL ACTIVE: ................................................................................................................................................. 14
ABSOLUTE MAXIMUM RATINGS ..................................................................................................................... 14
SYSTEM DESCRIPTION .......................................................................................................................... 15
1.0 THE TRANSMIT SECTION .................................................................................................................. 15
1.1 THE TRANSMIT INPUT INTERFACE ............................................................................................................ 15
1.2 OPERATING THE TRANSMITTER IN THE CLOCK MODE .......................................................................... 15
FIGURE 4. ILLUSTRATION ON HOW THE XRT59L921 SAMPLES THE DATA ON THE TXPOS_N AND TXNEG_N INPUT PINS................... 16
1.2.1 OPERATING THE TRANSMITTER IN THE CLOCKLESS MODE............................................................................. 16
1.2.2 SHUTTING OFF THE TRANSMITER.......................................................................................................................... 16
FIGURE 5. ILLUSTRATION ON HOW THE TERMINAL EQUIPMENT SHOULD APPLY DATA TO THE TRANSMIT SECTION OF A GIVEN CHANNEL (WITH-
IN THE XRT59L921), WHEN OPERATING IN THE CLOCKLESS MODE .................................................................................. 17
1.3 THE PULSE SHAPING CIRCUIT ................................................................................................................... 17
FIGURE 6. ILLUSTRATION OF THE ITU-T G.703 PULSE TEMPLATE FOR E1 APPLICATIONS ................................................................ 18
1.4 INTERFACING THE TRANSMIT SECTIONS OF THE XRT59L921 TO THE LINE ....................................... 18
FIGURE 7. ILLUSTRATION OF HOW TO INTERFACE THE TRANSMIT SECTIONS OF THE XRT59L921 TO THE LINE (FOR 75W APPLICATIONS)
19
FIGURE 8. ILLUSTRATION OF HOW TO INTERFACE THE TRANSMIT SECTIONS THE XRT59L921 TO THE LINE (FOR 120W APPLICATIONS)19
Transmit Transformer Recommendations ................................................................................................................. 19
The following Transformers are Recommended for Use........................................................................................... 20
MAGNETIC SUPPLIER INFORMATION .............................................................................................................. 20
2.0 THE RECEIVE SECTION ..................................................................................................................... 21
2.1 INTERFACING THE RECEIVE SECTIONS TO THE LINE (TRANSFORMER COUPLING) ......................... 21
FIGURE 9. RECOMMENDED SCHEMATIC FOR INTERFACING THE RECEIVE SECTIONS OF THE XRT59L921 TO THE LINE FOR 75W APPLICA-
TIONS (TRANSFORMER-COUPLING) .................................................................................................................................. 21
FIGURE 10. RECOMMENDED SCHEMATIC FOR INTERFACING THE RECEIVE SECTIONS OF THE XRT59L921 TO THE LINE FOR 120W APPLI-
CATIONS (TRANSFORMER-COUPLING) .............................................................................................................................. 22
TRANSFORMER RECOMENDATION ...................................................................................................... 23
Receive Transformer Recommendations .................................................................................................................. 23
2.2 INTERFACING THE XRT59L921 RECEIVE SECTION TO THE LINE (CAPACITIVE COUPLING) ............. 23
FIGURE 11. RECOMMENDED 75W CAPACITIVE COUPLING APPLICATION........................................................................................... 23
FIGURE 12. RECOMMENDED 120W TWISTED PAIR CAPACITIVE COUPLING APPLICATION .................................................................. 23
2.3 THE RECEIVE EQUALIZER BOCK ............................................................................................................... 24
2.4 THE PEAK DETECTOR AND SLICER BLOCK ............................................................................................. 24
2.5 THE LOS DETECTOR BLOCK ...................................................................................................................... 24
FIGURE 13. ILLUSTRATION OF THE SIGNAL LEVELS THAT THE RECEIVER SECTIONS (WITHIN XRT59L921) WILL DECLARE AND CLEAR LOS
24
FIGURE 14. THE BEHAVIOR OF THE LOS OUTPUT INDICATOR, IN RESPONSE TO THE LOSS OF SIGNAL, AND THE RESTORATION OF THE SIG-
NAL ................................................................................................................................................................................ 25
2.6 LOS MUTE DESCRIPTION ............................................................................................................................ 25
2.7 THE RECEIVE OUTPUT INTERFACE BLOCK ............................................................................................. 25
3.0 SHUTTING OFF THE TRANSMITTER ................................................................................................ 25
FIGURE 15. TRANSMIT TIMING DIAGRAM ......................................................................................................................................... 26
FIGURE 16. RECEIVE TIMING DIAGRAM ........................................................................................................................................... 26
APPLICATION INFORMATION................................................................................................................. 27
I