MC74AC353 Datasheet, PDF (2/8 Pages) Motorola, Inc – DUAL 4-INPUT MULTIPLEXER WITH 3-STATE OUTPUTS

MC74AC353 MC74ACT353
FUNCTIONAL DESCRIPTION
The MC74AC353/74ACT353 contains two identical
4-input multiplexers with 3-state outputs. They select two bits
from four sources selected by common Select inputs (S0, S1).
The 4-input multiplexers have individual Output Enable (OEa,
OEb) inputs which, when HIGH, force the outputs to a high
impedance (High Z) state. The logic equations for the outputs
are shown below:
Za = OEa•(I0a•S1•S0+I1a•S1•S0+
I2a•S1•S0+I3a•S1•S0)
Zb = OEb•(I0b•S1•S0+I1b•S1•S0+
I2b•S1•S0+I3b•S1•S0)
If the outputs of 3-state devices are tied together, all but one
device must be in the high impedance state to avoid high
currents that would exceed the maximum ratings. Designers
should ensure that Output Enable signals to 3-state devices
whose outputs are tied together are designed so that there is
no overlap.
LOGIC DIAGRAM
OEb I3b
I2b
I1b
I0b
S0
S1
I3a
I2a
I1a
I0a OEa
Zb
Za
Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.
FACT DATA
5-2