MH88634B
Central Office Interface Circuit
Advance Information
Features
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Loop Start Trunk Interface
600Ω
& 900Ω
Input Impedance
2-4 Wire Conversion
Line state Detection Outputs:
- Forward Loop
- Reverse Loop
- Ringing Voltage
- Switch Hook
One Relay Driver
On-Hook Reception
Small footprint area
Meets FCC Part 68 Leakage Current
Requirements
DS5061
ISSUE 6
January 1999
Ordering Information
MH88634BV-2
21 Pin SIL Package
MH88634BT-2
21 Pin 90° L/F Package
MH88634BV-4
21 Pin SIL Package
0°C to 70°C
Description
The Mitel MH88634-2 Central Office Interface Circuit
trunk provides a complete analogue and signalling
link between audio switching equipment and a
telephone Line. The device is available in a single in
line package for high packing densities or with a lead
frame formed at 90° for low clearance applications.
The device is fabricated as a thick film hybrid
incorporating various technologies for optimum
circuit design and very high reliability.
This part supercedes the MH88634-2 and is pin for pin
compatible.
We advise that the B rev parts are fully tested.
However, we do not expect to see changes between
MH88634-2 and MH88634BV-2.
The component design has been changed to
improve the general performance of the part. It is
also now capable of operating at a 24V battery.
Applications
Interface to Central Office for:
• PABX
• Key Telephone Systems
• Channel Bank
• Voice Mail
• Terminal Equipment
• Digital Loop Carrier
• Optical Multiplexer
RV
FL
RL
SHK
XLA XLB XLC XLD
VCC
VEE
AGND
Status
Detection
TIP
Dummy
Ringer
RING
LRC
LRD
Loop Relay
Driver
Line
Termination
2 - 4 Wire
Hybrid
Receive
Gain
RX
Transmit
Gain
TX
Impedance
Matching
Network
Balance
VRLY
Figure 1 - Functional Block Diagram
2-265
MITEL [ MITEL NETWORKS CORPORATION ]
