The MC3450, MC3550, MC3452, and MC3552 are quad differential line receivers designed for use in balanced and unbalanced digital data transmission. The MC34/3550 and MC34/3552 are the same except that the MC3450 and MC3550 have 3-state outputs whereas the MC3452 and MC3552 have open-collector outputs, which permit the wire-AND function with similar output devices. The 3-state and opencollector outputs permit connection directly to a bus-organized system.