DS3487
(RS-422/423 LINE DRIVERS AND RECEIVERS)
Quad TRI-STATE Line Driver

            +-----------+
    INPUT A |1  +--+  16| VCC
   OUTPUT A |2        15| INPUT D
   OUTPUT A |3        14| OUTPUT D
A/B CONTROL |4  DS34  13| OUTPUT D
   OUTPUT B |5   87   12| C/D CONTROL
   OUTPUT B |6        11| OUTPUT C
    INPUT B |7        10| OUTPUT C
        GND |8         9| INPUT C
            +-----------+