5-506

FAST AND LS TTL DATA

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)

OUTPUT

S0

S1

E

I0

I1

I2

I3

Z

X

X

H

X

X

X

X

H

L

L

L

L

X

X

X

H

L

L

L

H

X

X

X

L

H

L

L

X

L

X

X

H

H

L

L

X

H

X

X

L

L

H

L

X

X

L

X

H

L

H

L

X

X

H

X

L

H

H

L

X

X

X

L

H

H

H

L

X

X

X

H

L

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

GUARANTEED OPERATING RANGES

Symbol

Parameter

Min

Typ

Max

Unit

VCC

Supply Voltage

54

74

4.5

4.75

5.0

5.0

5.5

5.25

V

TA

Operating Ambient Temperature Range

54

74

– 55

0

25

25

125

70

°C

IOH

Output Current — High

54, 74

– 0.4

mA

IOL

Output Current — Low

54

74

4.0

8.0

mA