Nxp 74hc series logic devices nxp 74hc4051d 652 the 74hc4051d is an 8 channel analog multiplexerdemultiplexer with three digital select inputs s0 to s2 an active low enable input e eight independent inputsoutputs y0 to y7 and a common inputoutput z with e low one of the eight switches is selected low impedance on state by s0 to s2 with e high all switches are in the high impedance off state independent of s0 to s2vcc and gnd are the supply voltage pins for the digital con