MH88500IN

® MH88500IN Hybrid Subscriber Line Interface Circuit (SLIC) Preliminary Information Features Differential to single ended conversion No transformers required Minimum installation space Off-Hook detection and LED indicator drive Relay drive output Battery and ringing feed to line Logic interface: MUTE, OFHK, RC Mute of incoming audio Dial pulse detection Voltage surge protection MH88500IN ISSUE 1 April 1995 Ordering Information 20 Pin SIL Package 0° C to 70° C Description The Mitel MH88500IN Subscriber Line Interface Circuit provides a complete interface between the telephone line and a speech switch requiring only single bidirectional switch per crosspoint. The functions provided by the MH88500IN include bidirectional differential to single ended conversion in the speech path, line battery feed, ringing feed and loop and dial pulse detection. The device is fabricated as a thick film hybrid in a 20-pin ‘single-inline’ package allowing optimum circuit board packing density. Applications Line Interface for: PABX Intercoms Key Systems VA1 VA2 VB VC1 GND TIP RING RING FEED Loop Feed/ Ring Feed Speech Circuit JUNCTOR VA2 CD VB MUTE OFHK RD RC RGND Loop Detection Relay Drive Circuit LED THRESH ADJ VC2 Figure 1 - Functional Block Diagram 2-43 MH88500IN TIP VA1 RING RING FEED IC VC1 GND VB LED OFHK THRESH ADJ VA2 GND VC2 MUTE JUNCTOR RD RGND RC CD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Preliminary Information Figure 2 - Pin...