The MM78C30 MM88C30 is a dual differential line driver that also performs the dual four-input NAND or dual four-input AND function The absence of a clamp diode to VCC in the input protection circuitry of the MM78C30 MM88C30 allows a CMOS user to interface systems operating at different voltage levels Thus a CMOS digital signal source can operate at a VCC voltage greater than the VCC voltage of the MM78C30 line driver The differential output of the MM78C30 MM88C30 eliminates ground-loop errors