Philips Semiconductors

Product specification

74F521

8-bit identity comparator

2

May 15, 1990

853–0372 99601

FEATURES

DESCRIPTION

The 74F521 is an expandable 8-bit comparator. It compares two

words of up to 8 bits each and provides a Low output when the two

active-Low enable input.

TYPE

TYPICAL

PROPAGATION

DELAY

TYPICAL

SUPPLY CURRENT

(TOTAL)

74F521

7.0ns

24mA

PIN CONFIGURATION

SF00273

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

A0

B0

A1

B1

A2

B2

A3

B3

GND

B7

A7

B6

A6

B5

B4

A5

A4

ORDERING INFORMATION

DESCRIPTION

COMMERCIAL RANGE

PKG DWG #

20-pin plastic DIP

N74F521N

SOT146-1

20-pin plastic SOL

N74F521D

SOT163-1

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

PINS

DESCRIPTION

74F (U.L.) HIGH/LOW

LOAD VALUE HIGH/LOW

A0 – A7

Word A inputs

1.0/1.0

20

µA/0.6mA

B0 – B7

Word B inputs

1.0/1.0

20

µA/0.6mA

Expansion or Enable input (active Low)

1.0/1.0

20

µA/0.6mA

Identity output (active Low)

50/33

1.0mA/20mA

NOTE: One (1.0) FAST unit load is defined as: 20

µA in the High state and 0.6mA in the Low state.

LOGIC SYMBOL

19

GND = Pin 10

SF00274

2

3

4

5

6

7

8

9

11

12

13

14

15

A0

B0

A1

B1

A2

B2

A3

B3

A4

B4

A5

B5

A6

16

17

18

B6

A7

B7

1

IEC/IEEE SYMBOL

SF00275

COMP

19

2

4

6

8

11

13

15

17

0

3

A=B

A

3

5

7

9

12

14

15

18

0

7

B

1

EN