MH88631

® MH88631 Central Office Interface (LS/GS) Preliminary Information 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 600 Ω or AT&T compromise balance network -1 version: 20Hz Ringing Voltage -2 version: 50Hz Ringing Voltage ISSUE 4 April 1995 Ordering Information MH88631-1 MH88631-2 40 Pin SIL Package 40 Pin SIL Package 0° C to 70° C 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. Applications PBX Channel bank Intercom Key System RG FC RV RC TG LPGND RINGND VCC+ VCC- AGND T R Signal Detection Circuitry Ring Ground Relay Driver 1 Relay Driver 2 RC1 RD1 RGND CD RD2 RC2 NETBAL Network Balance VTR+ VTRRXINRXIN+ Active Termination Audio Section Circuitry (2-4 Wire) GSX VX VR GSR QB QE XA XB XC VDD VEE RXOUT TXIN+ TXIN- Figure 1 - Functional Block Diagram 2-225 MH88631 LPGND VDD RINGND T R VTRVTR+ XC XA QE AGND RXIN+ RXINVEE TG RC RV FC RG QB Preliminary Information 1 2 3 4 5 6 7 8 9 1...