SN54 / 74LS352
FUNCTIONAL DESCRIPTION
The SN54 / 74LS352 is a Dual 4-Input Multiplexer. It selects
two bits of data from up to four sources under the control of the
common Select Inputs (S0, S1). The two 4-input multiplexer
circuits have individual active LOW Enables (Ea, Eb) which
can be used to strobe the outputs independently. When the
Enables (Ea, Eb) are HIGH, the corresponding outputs (Za, Zb)
are forced HIGH.
The logic equations for the outputs are shown below.
Za = Ea • (I0a • S1 • S0 + I1a • S1 • S0 + I2a • S1 • S0 + I3a • S1 • S0)
Zb = Eb • (I0b • S1 • S0 + I1b • S1 • S0 + I2b • S1 • S0 + I3b • S1 • S0)
The SN54 / 74LS352 can be used to move data from a group
of registers to a common output bus. The particular register
from which the data came would be determined by the state of
the Select Inputs. A less obvious application is a function gen-
erator. The SN54 / 74LS352 can generate two functions of
three variables. This is useful for implementing highly irregular
random logic.
TRUTH TABLE
SELECT INPUTS
INPUTS (a or b)
S0
S1
E
I0
I1
I2
X
X
H
X
X
X
L
L
L
L
X
X
L
L
L
H
X
X
H
L
L
X
L
X
H
L
L
X
H
X
L
H
L
X
X
L
L
H
L
X
X
H
H
H
L
X
X
X
H
H
L
X
X
X
H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
OUTPUT
I3
Z
X
H
X
H
X
L
X
H
X
L
X
H
X
L
L
H
H
L
GUARANTEED OPERATING RANGES
Symbol
Parameter
VCC
Supply Voltage
TA
Operating Ambient Temperature Range
IOH
Output Current — High
IOL
Output Current — Low
Min
Typ
Max
Unit
54
4.5
5.0
5.5
V
74
4.75
5.0
5.25
54
– 55
25
125
°C
74
0
25
70
54, 74
– 0.4
mA
54
4.0
mA
74
8.0
FAST AND LS TTL DATA
5-506