4-160

FAST AND LS TTL DATA

DUAL 4-INPUT MULTIPLEXER

WITH 3-STATE OUTPUTS

The MC54/74F353 is a dual 4-input multiplexer with 3-state outputs. It can

select two bits of data from four sources using common Select inputs. The out-

puts may be individually switched to a high impedance state with a HIGH on

the respective Output Enable (OE) inputs, allowing the outputs to interface di-

rectly with bus-oriented systems.

FUNCTIONAL DESCRIPTION

The MC54/74F353 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.

CONNECTION DIAGRAM (TOP VIEW)

15

16

14

13

12

11

10

2

1

3

4

5

6

7

VCC

9

8

OEb

S0

I3b

I2b

I1b

I0b

Zb

OEa

S1

I3a

I2a

I1a

I0a

Za

GND

DUAL 4-INPUT MULTIPLEXER

WITH 3-STATE OUTPUTS

MC54/74F353

J SUFFIX

CERAMIC

CASE 620-09

N SUFFIX

PLASTIC

CASE 648-08

16

1

16

1

ORDERING INFORMATION

MC54FXXXJ

Ceramic

MC74FXXXN

Plastic

MC74FXXXD

SOIC

16

1

D SUFFIX

SOIC

CASE 751B-03

LOGIC SYMBOL

2

14

1

6

5

4

3

10

11

12

13

15

9

7

Za

Zb

S1 S0

OEa

I0a

I1a

I2a

I3a

I0b

I1b

I2b

I3b

OEb

VCC = PIN 16

GND = PIN 8