54ACT16821, 74ACT16821

20BIT BUSINTERFACE FLIPFLOPS

WITH 3STATE OUTPUTS

SCAS176A − JANUARY 1991 − REVISED APRIL 1996

4

POST OFFICE BOX 655303

POST OFFICE BOX 1443

recommended operating conditions (see Note 3)

54ACT16821

74ACT16821

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

VI

Input voltage

0

VCC

0

VCC

V

VO

Output voltage

0

VCC

0

VCC

V

IOH

High-level output current

−24

−24

mA

IOL

Low-level output current

24

24

mA

∆t/∆v

Input transition rise or fall rate

0

10

0

10

ns/V

TA

Operating free-air temperature

−55

125

−40

85

°C

NOTE 3: Unused inputs must be held high or low to prevent them from floating.

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

otherwise noted)

PARAMETER

TEST CONDITIONS

VCC

TA = 25°C

54ACT16821

74ACT16821

UNIT

PARAMETER

TEST CONDITIONS

VCC

MIN

TYP

MAX

MIN

MAX

MIN

MAX

UNIT

IOH = −50 A

4.5 V

4.4

4.4

4.4

IOH = −50 µA

5.5 V

5.4

5.4

5.4

VOH

IOH = −24 mA

4.5 V

3.94

3.8

3.8

V

VOH

IOH = −24 mA

5.5 V

4.94

4.8

4.8

V

IOH = −75 mA†

5.5 V

3.85

3.85

IOL = 50 A

4.5 V

0.1

0.1

0.1

IOL = 50 µA

5.5 V

0.1

0.1

0.1

VOL

IOL = 24 mA

4.5 V

0.36

0.44

0.44

V

VOL

IOL = 24 mA

5.5 V

0.36

0.44

0.44

V

IOL = 75 mA†

5.5 V

1.65

1.65

II

VI = VCC or GND

5.5 V

±0.1

±1

±1

µA

IOZ

VO = VCC or GND

5.5 V

±0.5

±5

±5

µA

ICC

VI = VCC or GND,

IO = 0

5.5 V

8

80

80

µA

∆ICC‡

One input at 3.4 V,

Other inputs at VCC or GND

5.5 V

0.9

1

1

mA

Ci

VI = VCC or GND

5 V

3

pF

Ci

VO = VCC or GND

5 V

11

pF

† Not more than one output should be tested at a time, and the duration of the test should not exceed 10 ms.

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

timing requirements over recommended operating free-air temperature range,

TA = 25°C

54ACT16821

74ACT16821

UNIT

MIN

MAX

MIN

MAX

MIN

MAX

UNIT

fclock

Clock frequency

0

70

0

70

0

70

MHz

tw

Pulse duration, CLK high or low

7

7

7

ns

tsu

Setup time, data before CLK

↑

7.5

7.5

7.5

ns

th

Hold time, data after CLK

↑

0.5

0.5

0.5

ns

PRODUCT PREVIEW information concerns products in the formative or

design phase of development. Characteristic data and other

specifications are design goals. Texas Instruments reserves the right to

change or discontinue these products without notice.