A
balanced circuit is circuitry for use with a
balanced line or the balanced line itself. Balanced lines are a common method of transmitting many types of electrical communication
signals between two points on two wires. In a balanced line the two signal lines are of a matched impedance to help ensure that interference induced in the line is
common-mode and can be removed at the receiving end by circuitry with good
common-mode rejection. To maintain the balance, circuit blocks which interface to the line, or are connected in the line, must also be balanced.