®
MH88612C
Subscriber Line Interface Circuit
Preliminary Information
Features
•
•
•
•
•
•
•
•
•
•
Input impedance 200Ω
+ 560Ω // 0.1µF
Transformerless 2-wire to 4-wire conversion
Battery and ringing feed to line
Off-hook and dial pulse detection
Ring ground over-current protection
Adjustable constant current feed
Relay drive output
Power VBat Denial
Wide Operating Range
Programmable Receive Gain
MH88612C
ISSUE 4
April 1995
Ordering Information
20 Pin SIL Package
0°C to 70°C
Description
The SLIC provides a complete interface between a
switching system and subscriber loop. Functions
provided include battery feed and ringing feed to the
subscriber line, 2-Wire to 4-Wire hybrid interfacing,
constant current feed and dial pulse detection. The
device is fabricated using thick film hybrid
technology in a 20-pin single in-line package.
Applications
Line interface for:
•
•
•
•
PABX
Intercoms
Key Telephone Systems
Control Systems
VBat
VDD VEE GNDA
GS
TF
TIP
RING
RF
RV
VRLY
RC
RD
Current & Voltage
Sensing
2-Wire to
4-Wire
Conversion
VR
VX
Over Current
Protection
Relay
Drive
Circuit
Loop
Supervision
VRef
CAP
Constant
Current
Feed
SHK
FIgure 1 - Functional Block Diagram
2-113
MITEL [ MITEL NETWORKS CORPORATION ]
