The 74HC4851 is a high-speed Si-gate CMOS device and is speci?ed in compliance with
JEDEC standard no. 7A.
The 74HC4851 is an 8-channel analog multiplexer/demultiplexer with three digital select
inputs (S0 to S2), an active-LOWenable input (E), eight independent inputs/outputs (Y0 to
Y7) and a common input/output (Z). The device features injection-current effect control,
which has excellent value in automotive applications where voltages in excess of the
supply voltage are common.
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.
The injection-current effect control allows signals at disabled analog input channels to
exceed the supply voltage without affecting the signal of the enabled analog channel.
This eliminates the need for external diode/resistor networks typically used to keep the
analog channel signals within the supply-voltage range.