The MC3487D is a four independent differential Line Driver designed to meet the specifications of ANSI TIA/EIA-422-B and ITU recommendation V.11. Each driver has a TTL-compatible input buffered to reduce current and minimize loading. The driver outputs utilize 3-state circuitry to provide high-impedance states at any pair of differential outputs when the appropriate output enable is at a low logic level. Internal circuitry is provided to ensure the high-impedance state at the differential outputs during power-up and power-down transition times, provided the output enable is low. It is designed for optimum performance when used with the MC3486 quadruple line receiver.