Philips 74als257 258 DATASHEETS

INTEGRATED CIRCUITS

74ALS257/74ALS258

Data selector/multiplexer

Product specification
IC05 Data Handbook

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1991 Feb 08

Philips Semiconductors Product specification

74ALS257/74ALS258Data selector/multiplexer

74ALS257 Quad 2-input data selector, non-inverting (3-State)
74ALS258 Quad 2-input data selector, inverting (3-State)

DESCRIPTION

The 74ALS257 is a quad 2-input multiplexer which selects 4 bits of
data from one of two sources under the control of a common select
input (S). The output enable input (OE
OE

is High, all of the outputs (Yn) are forced to a High impedance

state (3-State) regardless of all other input conditions.
Moving data from two registers to a common output bus is a typical

use of the 74ALS257. The state of the select input determines the
particular register from which data comes.

The device is the logic implementation of 4-pole, 2-position switch
where the position of the switch is determined by the logic levels
supplied to the select input. The 74ALS258 is similar but has
inverting outputs (Y

n).

) is active when Low. When

TYPE

74ALS257 7.0ns 7mA
74ALS258 7.0ns 7mA

ORDERING INFORMATION

DESCRIPTION COMMERCIAL RANGE

16-pin plastic DIP 74ALS257N, 74ALS258 SOT38-4

TYPICAL

PROPAGATION DELAY

ORDER CODE

V

= 5V ±10%,

CC

T

= 0°C to +70°C

amb

SUPPLY CURRENT

16-pin plastic SO 74ALS257D, 74ALS258D SOT109-1

16-pin plastic SSOP

Type II

74ALS257DB, 74ALS258DB SOT338-1

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS DESCRIPTION

74ALS (U.L.)

HIGH/LOW

Ina, Inb, Inc, Ind Data inputs 1.0/1.0 20µA/0.1mA

S Select input 1.0/1.0 20µA/0.1mA

OE Enable input 1.0/1.0 20µA/0.1mA

Ya – Yd, Ya – Yd Data outputs 20/240 0.4mA/24mA

NOTE: One (1.0) ALS unit load is defined as: 20µA in the High state and 0.1mA in the Low state.

LOAD VALUE

HIGH/LOW

TYPICAL

(TOTAL)

DRAWING

NUMBER

PIN CONFIGURATION – 74ALS257

16
15
14
13
12
11
107

98GND Yc

I0a
I1a

I0b
I1b

1

S

2
3
4

Ya

5
6

Yb

V
OE
I0d

I1d
Yd
I0c
I1c

PIN CONFIGURATION – 74ALS258

1
I0a
I1a

I0b
I1b

S

2

3

4

Y

a

5

6

Y

b

CC

SF00673

16
15
14
13
12
11
107

98GND Yc

V
OE
I0d

I1d
Yd
I0c
I1c

CC

SC00079

1991 Feb 08 853–1 130 01670

2

Philips Semiconductors Product specification

74ALS257/74ALS258Data selector/multiplexer

LOGIC SYMBOL – 74ALS257

2356111014

I0a I1a I0b I1b I0c I1c I0d

1

15

VCC = Pin 16
GND = Pin 8

S
OE

Ya Yb Yc Yd

47912

IEC/IEEE SYMBOL – 74ALS257

15
1

2
3

5
6

10
11

13
14

EN
G1

1
1

MUX

I1d

LOGIC SYMBOL – 74ALS258

13

1

15

VCC = Pin 16

SF00674

GND = Pin 8

2356111014

I0a I1a I0b I1b I0c I1c I0d
S
OE

Ya Yb Yc Yd

47912

13

I1d

SC00080

IEC/IEEE SYMBOL – 74ALS258

15
1

4

7

9

12

SF00675

2
3

5
6

10
11

13
14

EN
G1

1
1

MUX

4

7

9

12

SC00081

LOGIC DIAGRAM – 74ALS257

OE I0a I1a I0b I1b I0c I1c I0d I1d S

152356111014131

V

= Pin 16

CC

GND = Pin 8

47912

Ya Yb Yc Yd

SC00082

LOGIC DIAGRAM – 74ALS258

OE I0a I1a I0b I1b I0c I1c I0d I1d S

152356111014131

V

= Pin 16

CC

GND = Pin 8

47912

aYbYcYd

Y

SC00083

1991 Feb 08

3

Philips Semiconductors Product specification

SYMBOL

PARAMETER

UNIT

74ALS257/74ALS258Data selector/multiplexer

FUNCTION T ABLE – 74ALS257

FUNCTION T ABLE – 74ALS258

INPUTS OUTPUT

OE S I0n I1n Yn

H X X X Z

L L L X L
L L H X H
L H X L L
L H X H H

H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance “off” state

OE S I0n I1n Yn

H X X X Z

L L L X H
L L H X L
L H X L H
L H X H L

H = High voltage level
L = Low voltage level
X = Don’t care
Z = High impedance “off” state

ABSOLUTE MAXIMUM RATINGS

(Operation beyond the limit set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free air temperature range.)

SYMBOL

V

CC

V

IN

I

IN

V

OUT

I

OUT

T

amb

T

stg

Supply voltage –0.5 to +7.0 V
Input voltage –0.5 to +7.0 V
Input current –30 to +5 mA
Voltage applied to output in High output state –0.5 to V
Current applied to output in Low output state 48 mA
Operating free-air temperature range 0 to +70 °C
Storage temperature range –65 to +150 °C

PARAMETER RATING UNIT

INPUTS OUTPUT

CC

V

RECOMMENDED OPERATING CONDITIONS

T

V

V
V

I
I

CC

I

IK
OH
OL

amb

Supply voltage 4.5 5.0 5.5 V
High-level input voltage 2.0 V

IH

Low-level input voltage 0.8 V

IL

Input clamp current –18 mA
High-level output current –2.6 mA
Low-level output current 24 mA
Operating free-air temperature range 0 +70 °C

LIMITS

MIN NOM MAX

1991 Feb 08

4