TEXAS INSTRUMENTS SN54ALS21A Technical data

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SN54ALS21A, SN54AS21, SN74ALS21A, SN74AS21

DUAL 4-INPUT POSITIVE-AND GATES

SDAS085B – APRIL 1982 – REVISED DECEMBER 1994

• Package Options Include Plastic

Small-Outline (D) Packages, Ceramic Chip
Carriers (FK), and Standard Plastic (N) and
Ceramic (J) 300-mil DIPs

description

These devices contain two independent 4-input
positive-AND gates. They perform the Boolean
functions Y = A • B • C • D or Y = A
in positive logic.

The SN54ALS21A and SN54AS21 are
characterized for operation over the full military
temperature range of –55°C to 125°C. The
SN74ALS21A and SN74AS21 are characterized
for operation from 0°C to 70°C.

FUNCTION TABLE
(each gate)

INPUTS

A B C D

H H H H H

L XXX L
XLXX L
XXLX L
XXXL L

+ B + C + D

OUTPUT

Y

SN54ALS21A, SN54AS21 ...J PACKAGE

SN74ALS21A, SN74AS21 ...D OR N PACKAGE

SN54ALS21A, SN54AS21 . . . FK PACKAGE

NC
NC

1C

NC

1D

NC – No internal connection

1A
1B

NC

1C
1D
1Y

GND

3 2 1 20 19

4
5
6
7
8

9 10 11 12 13

(TOP VIEW)

1

14

2

13

3

12

4

11

5

10
6
7

(TOP VIEW)

1B1ANC

1Y

NC

GND

V

CC

2D
2C
NC
2B
2A

9

2Y

8

CC

V

2D

18

2C

17

NC

16

NC

15

NC

14

2B

2Y

2A

logic symbol

1

1A

2

1B

4

1C

5

1D

9

2A

10

2B

12

2C

13

2D

†

This symbol is in accordance with ANSI/IEEE Std 91-1984 and
IEC Publication 617-12.

Pin numbers shown are for the D, J, and N packages.

†

&

6

8

1Y

2Y

logic diagram (positive logic)

1

1A

2

1B
1C

1D

2A
2B

2C
2D

4
5

9
10

12
13

6

8

1Y

2Y

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.

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

Copyright  1994, Texas Instruments Incorporated

1

SN54ALS21A, SN54AS21, SN74ALS21A, SN74AS21

UNIT

PARAMETER

TEST CONDITIONS

UNIT

V

V

V

V

(

)

(

)

(INPUT)

(OUTPUT)

A, B, C, or D

Y

ns

DUAL 4-INPUT POSITIVE-AND GATES

SDAS085B – APRIL 1982 – REVISED DECEMBER 1994

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)

Supply voltage, V
Input voltage, V
Operating free-air temperature range, T

7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CC

7 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

I

: SN54ALS21A –55°C to 125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A

†

SN74ALS21A 0°C to 70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Storage temperature range –65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

†

Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

recommended operating conditions

SN54ALS21A SN74ALS21A

MIN NOM MAX MIN NOM MAX

V
V
V
I
I
T

OH
OL

A

Supply voltage 4.5 5 5.5 4.5 5 5.5 V

CC

High-level input voltage 2 2 V

IH

Low-level input voltage 0.8 0.8 V

IL

High-level output current –0.4 –0.4 mA
Low-level output current 4 8 mA
Operating free-air temperature –55 125 0 70 °C

electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)

SN54ALS21A SN74ALS21A

MIN TYP‡MAX MIN TYP‡MAX

V

IK

V

OH

OL

I

I

I

IH

I

IL

§

I

O

I

CCH

I

‡

All typical values are at VCC = 5 V, TA = 25°C.

§

The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.

CCL

VCC = 4.5 V, II = –18 mA –1.5 –1.5 V
VCC = 4.5 V to 5.5 V, IOH = –0.4 mA VCC –2 VCC –2 V

= 4.5

CC

VCC = 5.5 V, VI = 7 V 0.1 0.1 mA
VCC = 5.5 V, VI = 2.7 V 20 20 µA
VCC = 5.5 V, VI = 0.4 V –0.1 –0.1 mA
VCC = 5.5 V, VO = 2.25 V –20 –112 –30 –112 mA
VCC = 5.5 V, VI = 4.5 V 0.85 1.4 0.85 1.4 mA
VCC = 5.5 V, VI = 0 1.4 2.3 1.4 2.3 mA

IOL = 4 mA 0.25 0.4 0.25 0.4
IOL = 8 mA 0.35 0.5

switching characteristics (see Figure 1)

PARAMETER

t

PLH

t

¶

For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.

2

PHL

FROM
INPUT

POST OFFICE BOX 655303 • DALLAS, TEXAS 75265

OUTPUT

TO

VCC = 4.5 V to 5.5 V,
CL = 50 pF,
RL = 500 Ω,
TA = MIN to MAX

SN54ALS21A SN74ALS21A

MIN MAX MIN MAX

4 18 4 15
2 15 2 10

¶

UNIT