Texas Instruments SN54ALS645AJ, SN54AS645J, SN74ALS645A-1DW, SN74ALS645A-1DWR, SN74ALS645A-1N Datasheet

SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

	SDAS278 ± JANUARY 1995
• Bidirectional Bus Transceivers in	SN54ALS645A, SN54AS645 . . . J PACKAGE
High-Density 20-Pin Packages	SN74ALS645A, SN74AS645 . . . DW OR N PACKAGE

• True Logic

(TOP VIEW)

• 3-State Outputs

DIR

1

20

VCC

• Package Options Include Plastic

A1

2

19

OE

Small-Outline (DW) Packages, Ceramic

A2

3

18

B1

Chip Carriers (FK), and Standard Plastic (N)

A3

4

17

B2

and Ceramic (J) 300-mil DIPs

A4

5

16

B3

description

A5

6

15

B4

A6

7

14

B5

These octal bus transceivers are designed for

A7

8

13

B6

A8

9

12

B7

asynchronous two-way communication between

GND

10

11

B8

data buses. These devices transmit data from the

A bus to the B bus or from the B bus to the A bus,

depending on the level at the direction-control

SN54ALS645A, SN54AS645 . . . FK PACKAGE

(DIR) input. The output-enable (OE) input can be

(TOP VIEW)

used to disable the device so that the buses are

A2

A1

DIR

CC

OE

effectively isolated.

V

The -1 version of the SN74ALS645A is identical

A3

3

2

1

20 19

B1

to

the

standard

version,

except

that

the

4

18

recommended maximum IOL is increased to

A4

5

17

B2

B3

48 mA.

There

is

no

-1

version

of

the

A5

6

16

SN54ALS645A.

A6

7

15

B4

The SN54ALS645A and SN54AS645 are

A7

8

14

B5

9

10 11 12 13

characterized for operation over the full military

A8

GND

B8

B7 B6

temperature range of ±55°C to 125°C. The

SN74ALS645A

and

SN74AS645

are

characterized for operation from 0°C to 70°C.

FUNCTION TABLE

		INPUTS		OPERATION
	OE		DIR
		L	L	B data to A bus
		L	H	A data to B bus
		H	X	Isolation

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

Copyright 1995, Texas Instruments Incorporated

POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

1

SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SDAS278 ± JANUARY 1995

logic symbol²			logic diagram (positive logic)
19	G3		OE	19
OE
1	3 EN1 [BA]
DIR
	3 EN2 [AB]
2		18	DIR	1
	1
A1		B1
		2
3		17
A2		B2
4		16	A1	2	18	B1
A3		B3
5		15
A4		B4
6		14
A5		B5
7		13
A6		B6
8		12
A7		B7
9		11		To Seven Other Transceivers
A8		B8

²This symbol is in accordance with ANSI/IEEE Std 91-1984 and

IEC Publication 617-12.

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)³

Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . 7	V
Input voltage, VI: All inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . 7	V
I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 5.5	V
Operating free-air temperature range, TA: SN54ALS645A . . . . . . . . . . . . . . . . . . . . . . . . . . .	±55°C to 125°C
SN74ALS645A . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . 0°C to 70°C
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	±65°C to 150°C

³Stresses beyond those listed under ªabsolute maximum ratingsº 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 ªrecommended operating conditionsº is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

recommended operating conditions

				SN54ALS645A			SN74ALS645A			UNIT
				MIN	NOM	MAX	MIN	NOM	MAX
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					0.7			0.8	V
IOH	High-level output current					± 12			± 15	mA
IOL	Low-level output current					12			24	mA
									48§
TA	Operating free-air temperature			± 55		125	0		70	°C
§ Applies only to the -1 version and only if V		CC	is between 4.75 V and 5.25 V

2	POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

SN54ALS645A, SN54AS645, SN74ALS645A, SN74AS645

OCTAL BUS TRANSCEIVERS

WITH 3-STATE OUTPUTS

SDAS278 ± JANUARY 1995

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

PARAMETER

TEST CONDITIONS

SN54ALS645A

SN74ALS645A

UNIT

MIN

TYP²

MAX

MIN

TYP²

MAX

VIK

VCC =

4.5 V,

II = ± 18 mA

± 1.5

± 1.5

V

VCC =

4.5 V to 5.5 V,

IOH = ± 0.4 mA

VCC ± 2

VCC ± 2

VOH

IOH = ± 3 mA

2.4

3.2

2.4

3.2

V

VCC =

4.5 V

IOH = ± 12 mA

2

IOH = ± 15 mA

2

IOL = 12 mA

0.25

0.4

0.25

0.4

VOL

VCC =

4.5 V

IOL = 24 mA

0.35

0.5

V

IOL = 48 mA³

0.35

0.5

II

Control inputs

VCC =

5.5 V

VI = 7 V

0.1

0.1

mA

A or B ports

VI = 5.5 V

0.1

0.1

IIH

Control inputs

VCC = 5.5 V,

VI = 2.7 V

20

20

μA

A or B ports§

20

20

IIL

Control inputs

VCC = 5.5 V,

VI = 0.4 V

± 0.1

± 0.1

mA

A or B ports§

± 0.1

± 0.1

I

O

¶

V =

5.5 V,

V = 2.25 V

± 20

± 112

± 30

± 112

mA

CC

O

Outputs high

30

48

30

45

ICC

VCC =

5.5 V

mA

Outputs low

36

60

36

55

Outputs disabled

38

63

38

58

²

All typical values are at V

CC

= 5 V, T

= 25°C.

³

A

Applies only to the -1 version and only if V is between 4.75 V and 5.25 V

CC

§For I/O ports, the parameters IIH and IIL include the off-state output current.

¶The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS.

switching characteristics (see Figure 1)

					VCC = 4.5 V to 5.5 V,
					CL = 50 pF,
	FROM			TO	R1 = 500 Ω,
					R2 = 500		Ω
PARAMETER							,			UNIT
	(INPUT)			(OUTPUT)	T	= MIN to MAX#
					A
					SN54ALS645A			SN74ALS645A
					MIN	MAX		MIN	MAX
tPLH	A or B			B or A	1	19		3	10	ns
tPHL					1	14		3	10
tPZH				A or B	2	30		5	20	ns
	OE
tPZL					2	29		5	20
tPHZ				A or B	2	14		2	10	ns
	OE
tPLZ					2	30		4	15

# For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.

POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

3