The DS9622 is a dual line receiver designed to discriminate a worst case logic swing of 2V from a 10V common mode noise signal or ground shift. A 1.5V threshold is built into the differential amplifier to offer a TTL compatible threshold voltage and maximum noise immunity. The offset is obtained by use of current sources and matched resistors. The DS9622 allows the choice of output states with the input open, without affecting circuit performance by use of S3. A 130 terminating resistor is provided at the input of each line receiver. An enable is also provided for each line receiver. The output is TTL compatible. The output high level can be increased to 12V by tying it to a positive supply through a resistor. The output circuits allow wired-OR operation.