®
MH88630
Central Office Interface (LS/GS)
Preliminary Information
Features
•
•
Transformerless 2-4 Wire conversion
Line state detection outputs:
-
-
-
-
-
•
•
•
forward current
reverse current
ring ground
tip ground
ringing voltage
ISSUE 7
April 1995
Ordering Information
MH88630
40-Pin DIL Package
0°C to 70°C
Description
The Mitel MH88630 Central Office Trunk Interface
circuit provides a complete audio and signalling link
between an audio switching equipment and a central
office. The loop seize circuitry is controlled by an
external input to provide either a loop start or ground
start termination. The device is fabricated using thick
film hybrid technology to achieve high density circuit
design.
Programmable audio transmit and receive gain
Loop start or ground start termination
Selectable 600Ω or AT&T compromise balance
network
Applications
•
•
•
•
PBX Interface to Central Office
Channel bank
Intercom
Key system
RG FC
RV RC TG
LPGND RINGND
VCC+ VCC- AGND
T
R
Signal Detection
Circuitry
Ring
Ground
Relay
Driver 1
Relay
Driver 2
VTR+
VTR-
RXIN-
RXIN+
Network
Balance
Active
Termination
Audio Section
Circuitry
(2 - 4 Wire)
RC1
RD1
RGND
CD
RD2
RC2
NETBAL
GSX
VX
VR
GSR
QB QE XA XB
XC
VDD
VEE
RXOUT
TXIN+
TXIN-
Figure 1 - Functional Block Diagram
2-215
MITEL [ MITEL NETWORKS CORPORATION ]
