MH88500
®
Hybrid Subscriber Line Interface Circuit (SLIC)
Preliminary Information
Features
•
•
•
•
•
•
•
•
•
•
Differential to single ended conversion
No transformers required
Minimum installation space
Off-Hook detection and LED indicator drive
Relay drive output
Battery and ringing feed to line
Logic interface: MUTE, OFHK, RC
Mute of incoming audio
Dial pulse detection
Voltage surge protection
MH88500
ISSUE 5
April 1995
Ordering Information
20 Pin SIL Package
0°C to 70°C
Description
The Mitel MH88500 Subscriber Line Interface Circuit
provides a complete interface between the telephone
line and a speech switch requiring only single
bidirectional switch per crosspoint. The functions
provided by the MH88500 include bidirectional
differential to single ended conversion in the speech
path, line battery feed, ringing feed and loop and dial
pulse detection. The device is fabricated as a thick
film hybrid in a 20-pin ‘single-in-line’ package
allowing optimum circuit board packing density.
Applications
Line Interface for:
• PABX
•
•
Intercoms
Key Systems
VA
1
V
A2
V
B
V
C1
GND
TIP
RING
RING
FEED
Loop Feed/
Ring Feed
Speech Circuit
JUNCTOR
V
A2
CD
V
B
MUTE
OFHK
RD
RC
RGND
Loop Detection
Relay Drive
Circuit
LED
THRESH ADJ
V
C2
Figure 1 - Functional Block Diagram
2-33
MITEL [ MITEL NETWORKS CORPORATION ]
