4.4 Electrical Characteristics

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

PARAMETER

TEST CONDITIONS

VCC

TA = 25°C

SN54ACT74

SN74ACT74

UNIT

MIN

TYP

MAX

MIN

MAX

MIN

MAX

VOH

IOH = –50µA

4.5V

4.4

4.49

4.4

4.4

V

5.5V

5.4

5.49

5.4

5.4

IOH = –24mA

4.5V

3.86

3.7

3.76

5.5V

4.86

4.7

4.76

IOH = –50mA†(1)

5.5V

3.86

IOH = –75mA†(1)

5.5V

3.85

VOL

IOL = 50µA

4.5V

0.001

0.1

0.1

0.1

V

5.5V

0.001

0.1

0.1

0.1

IOL = 24mA

4.5V

0.36

0.5

0.44

5.5V

0.36

0.5

0.44

IOL = 50mA†(1)

5.5V

1.65

IOL = 75mA†(1)

5.5V

1.65

II

VI = VCC or GND

5.5V

±0.1

±1

±1

µA

ICC

VI = VCC or GND, IO = 0

5.5V

2

40

20

µA

ΔICC‡ (2)

One input at 3.4V,

Other inputs at GND or VCC

5.5V

0.6

1.6

1.5

mA

Ci

VI = VCC or GND

5V

3

pF

(1)

Not more than one output should be tested at a time, and the duration of the test should not exceed 2ms.

(2)

This is the increase in supply current for each input that is at one of the specified TTL voltage levels, rather than 0V or VCC.

4.5 Timing Requirements

over recommended operating free-air temperature range (unless otherwise noted) (see Load Circuit and Voltage Waveforms)

TA = 25°C

SN54ACT74

SN74ACT74

UNIT

MIN

MAX

MIN

MAX

MIN

MAX

fclock

Clock frequency

145

85

125

MHz

tw

Pulse duration

PRE or CLR low

5

7

6

ns

CLK

5

7

6

tsu

Setup time, data before CLK↑

Data

3

4

3.5

ns

0

0.5

0

th

Hold time, data after CLK↑

PRE or CLR

inactive

1

1

1

ns

4.6 Switching Characteristics

over recommended operating free-air temperature range (unless otherwise noted) (see Load Circuit and Voltage

Waveforms)

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

SN54ACT74

SN74ACT74

UNIT

TA = 25°C

MIN

MAX

TA = 25°C

MIN MAX

MIN

TYP

MAX

MIN TYP MAX

fmax

145

210

85

145

210

125

MHz

tPLH

PRE or

CLR

Q or Q

1

5.5

9.5

1

11.5

3

5.5

9.5

2.5 10.5

ns

tPHL

1

6

10

1

12.5

3

6

10

3 11.5

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SN54ACT74, SN74ACT74

SCAS520J – AUGUST 1995 – REVISED APRIL 2025

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