The DS1648 DS3648 and DS1678 DS3678 are quad 2-input multiplexers with TRI-STATE outputs designed to drive the large capacitive loads (up to 500 pF) associated with MOS memory systems A PNP input structure is employed to minimize input currents so that driver loading in large memory systems is reduced The circuit employs Schottkyclamped transistors for high speed and TRI-STATE outputs for bus operation