®
MH89626C
OPS/DID SLIC
Preliminary Information
Features
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Transformerless 2-4 wire conversion
Constant current with constant voltage fallback
for long loops
Long length capability (R
Loop
> 1850Ω)
Input impedance
200Ω + 560Ω // 0.1µF (MH89626C-02)
200Ω + 680Ω // 0.1µF (MH89626C-04)
Ring trip filter with auto ring trip
Three relay drivers
Built-in Tip/Ring reversal capability on the
hybrid
Serial control interface
External or software programmable receive
gain, -3.5 or -7.0dB
MH89626C-02
MH89626C-04
ISSUE 3
May 1995
Ordering Information
38 Pin SIL Package
38 Pin SIL Package
0°C to 70°C
Description
The MH89626C SLIC provides all of the functions
required to interface 2-wire off premise subscriber
loops to a serial TDM, PCM, switching network of a
modern PBX. The MH89626C is manufactured
using thick film hybrid technology which offers high
voltage capability, reliability and high density
resulting in significant printed circuit board area
saving of the line cards. A complete line card can
be
implemented
with
very
few external
components.
The SLIC has a simple serial control interface to
control the receive gain setting, relay drivers for
ringing, and Tip/Ring reversal for DID operation.
Applications
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Off-Premise PBX Line Cards
DID (Direct Inward Dial) Line Cards
Central Office Line Cards
LGND
TF
TIP
Tip
Drive
VDD
VEE
LCA
AGND
RGND
VREF
F1i
C2i
2W/4W
Conversion
Current
& Voltage
Sensing
Constant
Current &
Voltage
Control
Gain
Adjust
MT8967
A-Law
Filter/Codec
Do
Di
GS
SD2
SD3
SD0
SD1
Relay
Driver 2
RING
RF2
RF
VBat
Ring
Drive
Tip/Ring
Reversed
8-Bit
Shift
Register
SD4
Relay
Driver 3
CS
SDi
Auto Ring
Line
Supervision
Trip Filter
Relay
Drive 1
LED
SHK
VAC
VRLY
RD1
RD2
RD3
SD5 SD6 SD7
Figure 1 - Functional Block Diagram
2-285