The 74HC4051; 74HCT4051 is a high-speed Si-gate CMOS device and is pin compatible with Low-power Schottky TTL (LSTTL). The device is specified in compliance with JEDEC standard no. 7A. The 74HC4051; 74HCT4051 is an 8-channel analog multiplexer/demultiplexer with three digital select inputs (S0 to S2), an active-LOW enable input (E), eight independent inputs/outputs (Y0 to Y7) and a common input/output (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 S2. VCC and GND are the supply voltage pins for the digital control inputs (S0 to S2, and E). The VCC to GND ranges are 2.0 V to 10.0 V for 74HC4051 and 4.5 V to 5.5 V for 74HCT4051. The analog inputs/outputs (Y0 to Y7, and Z) can swing between VCC as a positive limit and VEE as a negative limit. VCC − VEE may not exceed 10.0 V. For operation as a digital multiplexer/demultiplexer, VEE is connected to GND (typically ground).