MH88634 Datasheet, PDF (1/8 Pages) Mitel Networks Corporation – Central Office Interface Circuit Preliminary Information

MH88634
®
Central Office Interface Circuit
Preliminary Information
Features
• Loop Start Trunk Interface
• 600 ohm input impedance, -2 variant
• Line state detection outputs: forward loop,
reverse loop, ringing voltage, switch hook
On-hook reception
• Transformerless 2W to 4W conversion
• One loop start relay driver
• +/- 5V operation
• Small footprint area (<4.75cm²)
Applications
Interface to Central Office for:
• PABX
• Key Telephone Systems
• Channel Bank
• Voice Mail
• Terminal Equipment
• Digital Loop Carrier
• Optical Multiplexer
ISSUE 2
April 1995
Ordering Information
MH88634-2 21 Pin SIL Package
0°C to 70°C
Description
The Mitel MH88634 Central Office Trunk Interface
circuit provides a complete audio and signalling link
between audio switching equipment and a central
office. The functions provided by the MH88634
include 2-4 Wire conversion, 600 ohm input
impedance and network balance. The device is
fabricated as a thick film hybrid incorporating various
technologies for optimum circuit design and very
high reliability.
RING
TIP
VDD VEE AGND RV FL RL SHK
Dummy
Ringer
Status
Detection
XLA
XLB
XLC
XLD
LRC
LRD
Loop
Termination
Loop Relay
Driver
VRLY RGND
2-4 Wire Hybrid
Impedance
Matching
Network
Balance
Figure 1 - Functional Block Diagram
Receive
Rx
Gain
Transmit
Gain
Tx
2-253