SN54F521, SN74F521

8-BIT IDENTITY COMPARATORS

SDFS091 – MARCH 1987 – REVISED OCTOBER 1993

2–3

POST OFFICE BOX 655303

– 0.5 V to 7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

– 1.2 V to 7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Input current range

– 30 mA to 5 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Voltage range applied to any output in the high state

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Current into any output in the low state

40 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operating free-air temperature range:

SN54F521

– 55

°C to 125°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

SN74F521

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.

NOTE 1: The input voltage ratings may be exceeded provided the input current ratings are observed.

recommended operating conditions

SN54F521

SN74F521

UNIT

MIN

NOM

MAX

MIN

NOM

MAX

UNIT

VCC

Supply voltage

4.5

5

5.5

4.5

5

5.5

V

VIH

High-level input voltage

2

2

V

VIL

Low-level input voltage

0.8

0.8

V

IIK

Input clamp current

–18

–18

mA

IOH

High-level output current

–1

–1

mA

IOL

Low-level output current

20

20

mA

TA

Operating free-air temperature

–55

125

0

70

°C

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

otherwise noted)

PARAMETER

TEST CONDITIONS

SN54F521

SN74F521

UNIT

PARAMETER

TEST CONDITIONS

MIN

TYP‡

MAX

MIN

TYP‡

MAX

UNIT

VIK

VCC = 4.5 V,

II = – 18 mA

– 1.2

– 1.2

V

VOH

VCC = 4.5 V,

IOH = – 1 mA

2.5

3.4

2.5

3.4

V

VOH

VCC = 4.75 V,

IOH = – 1 mA

2.7

V

VOL

VCC = 4.5 V,

IOL = 20 mA

0.3

0.5

0.3

0.5

V

II

VCC = 5.5 V,

VI = 7 V

100

100

µA

IIH

VCC = 5.5 V,

VI = 2.7 V

20

20

µA

IIL

VCC = 5.5 V,

VI = 0.5 V

– 0.6

– 0.6

mA

IOS§

VCC = 5.5 V,

VO = 0

–60

– 150

–60

– 150

mA

ICC

VCC = 5.5 V,

See Note 2

21

32

21

32

mA

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

§ Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.

NOTE 2: ICC is measured with all inputs at 4.5 V.