SN54HCT645, SN74HCT645

OCTAL BUS TRANSCEIVERS

WITH 3STATE OUTPUTS

SCLS019D − MARCH 1984 − REVISED AUGUST 2003

3

POST OFFICE BOX 655303

recommended operating conditions (see Note 3)

SN54HCT645

SN74HCT645

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

VCC = 4.5 V to 5.5 V

2

2

V

VIL

Low-level input voltage

VCC = 4.5 V to 5.5 V

0.8

0.8

V

VI

Input voltage

0

VCC

0

VCC

V

VO

Output voltage

0

VCC

0

VCC

V

∆t/∆v

Input transition rise/fall time

500

500

ns

TA

Operating free-air temperature

−55

125

−40

85

°C

NOTE 3: All unused inputs of the device must be held at VCC or GND to ensure proper device operation. Refer to the TI application report,

Implications of Slow or Floating CMOS Inputs, literature number SCBA004.

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

otherwise noted)

PARAMETER

TEST CONDITIONS

VCC

TA = 25°C

SN54HCT645

SN74HCT645

UNIT

PARAMETER

TEST CONDITIONS

VCC

MIN

TYP

MAX

MIN

MAX

MIN

MAX

UNIT

VOH

VI = VIH or VIL

IOH = −20 µA

4.5 V

4.4

4.499

4.4

4.4

V

VOH

VI = VIH or VIL

IOH = −6 mA

4.5 V

3.98

4.3

3.7

3.84

V

VOL

VI = VIH or VIL

IOL = 20 µA

4.5 V

0.001

0.1

0.1

0.1

V

VOL

VI = VIH or VIL

IOL = 6 mA

4.5 V

0.17

0.26

0.4

0.33

V

II

DIR or OE

VI = VCC or 0

5.5 V

±0.1

±100

±1000

±1000

nA

IOZ

A or B

VO = VCC or 0

5.5 V

±0.01

±0.5

±10

±5

µA

ICC

VI = VCC or 0,

IO = 0

5.5 V

8

160

80

µA

∆ICC†

One input at 0.5 V or 2.4 V,

Other inputs at 0 or VCC

5.5 V

1.4

2.4

3

2.9

mA

Ci

DIR or OE

4.5 V

to 5.5 V

3

10

10

10

pF

† 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.

(unless otherwise noted) (see Figure 1)

PARAMETER

FROM

TO

VCC

TA = 25°C

SN54HCT645

SN74HCT645

UNIT

PARAMETER

FROM

(INPUT)

TO

(OUTPUT)

VCC

MIN

TYP

MAX

MIN

MAX

MIN

MAX

UNIT

tpd

A or B

B or A

4.5 V

16

22

33

28

ns

tpd

A or B

B or A

5.5 V

14

20

30

25

ns

ten

OE

A or B

4.5 V

25

46

69

58

ns

ten

OE

A or B

5.5 V

22

41

62

52

ns

tdis

OE

A or B

4.5 V

26

40

60

50

ns

tdis

OE

A or B

5.5 V

23

36

54

45

ns

tt

A or B

4.5 V

9

12

18

15

ns

tt

A or B

5.5 V

8

11

16

14

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.