®
MH88634
Central Office Interface Circuit Preliminary Information
Features
• • • Loop Start Trunk Interface 600 ohm i...
®
MH88634
Central Office Interface Circuit Preliminary Information
Features
Loop Start Trunk Interface 600 ohm input impedance, -2 variant Line state detection outputs: forward loop, reverse loop, ringing
voltage, switch hook On-hook reception Transformerless 2W to 4W conversion One loop start relay driver +/- 5V operation Small footprint area (<4.75cm 2)
MH88634-2
ISSUE 2
April 1995
Ordering Information
21 Pin SIL Package
0° C to 70° C
Description
The Mitel MH88634 Central Office Trunk Interface circuit provides a complete audio and signalling link between audio switching equipment and a central office. The functions provided by the MH88634 include 2-4 Wire conversion, 600 ohm input impedance and network balance. The device is fabricated as a thick film hybrid incorporating various technologies for optimum circuit design and very high reliability.
Applications
Interface to Central Office for: PABX Key Telephone Systems Channel Bank Voice Mail Terminal Equipment Digital Loop Carrier Optical Multiplexer
RING
TIP
VDD VEE AGND RV
FL
RL
SHK
Dummy Ringer
Status Detection
XLA XLB XLC XLD LRC LRD
Loop Termination 2-4 Wire Hybrid Loop Relay Driver Impedance Matching Network Balance
Receive Gain
Rx
Transmit Gain
Tx
VRLY
RGND
Figure 1 - Functional Block Diagram
2-253
MH88634
TIP RING XLA XLD XLB XLC IC IC IC SHK Rx VEE Tx RV FL RL VDD AGND LRC VRLY LRD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
Preliminary Information
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