SN74ALS155

DUAL 2-LINE TO 4-LINE DECODER/DEMULTIPLEXER

SDAS140 — NOVEMBER 1987

POST OFFICE BOX 655303

Copyright

1

PRODUCTION DATA information is current as of

publication date. Products conform to specifications

per the terms of Texas Instruments standard

warranty.

Production

processing

does

not

necessarily include testing of all parameters.

Dual 2-Line to 4-Line Decoder

Dual 1-Line to 4-Line Demultiplexer

3-Line to 8-Line Decoder

1-Line to 8-Line Demultiplexer

Decoding or Demultiplexing Larger Words

Outline” Packages and Standard Plastic

300-mil DIPs

description

The

′ALS155 circuits feature dual 1-line to 4-line

demultiplexers

with

individual

strobes

and

common binary-address inputs in a single 16-pin

package. When both sections are enabled, the

common

binary-address

inputs

sequentially

select and route associated input data to the

appropriate output of each section. The individual

strobes permit enabling or disabling each of the

4-bit sections as desired.

Data applied to input 1C is inverted at its outputs

and data applied at input 2C is not inverted

through its outputs. The inverter following the 1C

data input permits use of the

′ALS155 as a 3-line

to 8-line demultiplexer without external gating. All

inputs

are

clamped

with

high-performance

Schottky diodes to suppress line ringing and

simplify system design.

The SN74ALS155 is characterized for operation

from 0

°C to 70°C.

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

1C

1G

B

1Y3

1Y2

1Y1

1Y0

GND

2C

2G

A

2Y3

2Y2

2Y1

2Y0

D or N Package

(Top View)

logic diagram (positive logic)

OUTPUT

1Y0

7

OUTPUT

1Y1

6

5 OUTPUT

1Y2

4 OUTPUT

1Y3

9 OUTPUT

2Y0

10 OUTPUT

2Y1

11 OUTPUT

2Y2

12 OUTPUT

2Y3

STROBE

1G

2

DATA

1C

1

SELECT

B

3

SELECT

A

13

DATA

2C

15

STROBE

1G

14