Description
The Mitel MH88631-1, 2 Central Office Trunk Interface circuit provides a complete audio and signalling link between audio switching equipment and a central office. The loop seize circuitry is controlled by an external input to provide either a loop start of ground start termination. The device is fabricated using thick film ceramic technology to achieve high density circuit design.

Features
• Transformerless 2-4 wire conversion
• Line state detection outputs
• - forward current
• - reverse current
• - ring ground
• - tip ground
• - ringing voltage
• Programmable audio transmit and receive gain
• Loop start or ground start termination
• Selectable 600Ω or AT&T compromise balance network
• -1 version: 20Hz Ringing Voltage
• -2 version: 50Hz Ringing Voltage

Applications
• PBX
• Channel bank
• Intercom
• Key System