Texas Instruments SN74ALS641A-1DW, SN74ALS641A-1DWR, SN74ALS641A-1N, SN74ALS641ADW, SN74ALS641ADWR Datasheet

SN74ALS641A, SN74ALS642A, SN74AS641

OCTAL BUS TRANSCEIVERS

WITH OPEN-COLLECTOR OUTPUTS

SDAS300 ± MARCH 1995

• Bidirectional Bus Transceivers in			DW OR N PACKAGE
High-Density 20-Pin Packages				(TOP VIEW)
• Choice of True or Inverting Logic			DIR				VCC
					1	20
• Package Options Include Plastic
			A1		2	19	OE
Small-Outline (DW) Packages and
			A2		3	18	B1
Standard Plastic (N) 300-mil DIPs
			A3		4	17	B2
			A4		5	16	B3
	DEVICE	LOGIC	A5		6	15	B4
	SN74ALS641A, SN74AS641	True	A6		7	14	B5
	SN74ALS642A	Inverting	A7		8	13	B6
description			A8		9	12	B7
			GND		10	11	B8

These octal bus transceivers are designed for asynchronous two-way communication between

data buses. These devices transmit data from the A bus to the B bus or from the B bus to the A bus, depending upon the level at the direction-control (DIR) input. The output-enable (OE) input disables the device so that the buses are effectively isolated.

The -1 versions of the SN74ALS641A and SN74ALS642A are identical to the standard versions, except that the recommended maximum IOL is increased to 48 mA in the -1 versions.

The SN74ALS641A, SN74ALS642A, and SN74AS641 are characterized for operation from 0°C to 70°C.

FUNCTION TABLE

	INPUTS		OPERATION
			SN74ALS641A
	OE	DIR		SN74ALS642A
			SN74AS641
	L	L	B data to A bus					data to A bus
						B
	L	H	A data to B bus
					A			data to B bus
	H	X	Isolation					Isolation

logic symbols²

SN74ALS641A, SN74AS641

SN74ALS642A

19

19

G3

OE

OE

G3

1

1

DIR

3 EN1 [BA]

DIR

3 EN1 [BA]

3 EN2 [AB]

3 EN2 [AB]

A1	2	18	A1	2	18
	1	B1		1	B1
	2				2
A2	3	17	A2	3	17
		B2			B2
A3	4	16	A3	4	16
		B3			B3
A4	5	15	A4	5	15
		B4			B4
A5	6	14	A5	6	14
		B5			B5
A6	7	13	A6	7	13
		B6			B6
A7	8	12	A7	8	12
		B7			B7
A8	9	11	A8	9	11
		B8			B8

² These symbols are in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12.

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

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SN74ALS641A, SN74ALS642A, SN74AS641

OCTAL BUS TRANSCEIVERS

WITH OPEN-COLLECTOR OUTPUTS

SDAS300 ± MARCH 1995

logic diagrams (positive logic)

SN74ALS641A, SN74AS641			SN74ALS642A
19		19
OE		OE
1		1
DIR		DIR
18	B1	2	18	B1
2
A1		A1

To Seven Other Transceivers

To Seven Other Transceivers

absolute maximum ratings over operating free-air temperature range (unless otherwise noted)²

Supply voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . . 7 V
Input voltage, VI: All inputs and I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . 7 V
Operating free-air temperature range, TA: SN74ALS641A, SN74ALS642A . . . . . . . . . . . . . . .	. . 0°C to 70°C
Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	±65°C to 150°C

²Stresses 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

				SN74ALS641A
				SN74ALS642A			UNIT
				MIN	NOM	MAX
VCC	Supply voltage			4.5	5	5.5	V
VIH	High-level input voltage			2			V
VIL	Low-level input voltage					0.8	V
VOH	High-level output voltage					5.5	V
IOL	Low-level output current					24	mA
						48³
TA	Operating free-air temperature			0		70	°C
³ 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

SN74ALS641A, SN74ALS642A, SN74AS641

OCTAL BUS TRANSCEIVERS

WITH OPEN-COLLECTOR OUTPUTS

SDAS300 ± MARCH 1995

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

					SN74ALS641A
	PARAMETER		TEST CONDITIONS		SN74ALS642A			UNIT
					MIN	TYP²	MAX
VIK			VCC = 4.5 V,	II = ± 18 mA			± 1.5	V
IOH			VCC = 4.5 V,	VOH = 5.5 V			0.1	mA
				IOL = 12 mA		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	mA
IIH		Control inputs	VCC = 5.5 V,	VI = 2.7 V			20	μA
		A or B ports§					20
IIL		Control inputs	VCC = 5.5 V,	VI = 0.4 V			± 0.1	mA
		A or B ports§					± 0.1
		SN74ALS641A	VCC = 5.5 V	Outputs high		25	37
ICC				Outputs low		33	47	mA
		SN74ALS642A	VCC = 5.5 V	Outputs high		8	15
				Outputs low		18	28

² All typical values are at VCC = 5 V, TA = 25°C.

³Applies only to the -1 version and only if VCC is between 4.75 V and 5.25 V § For I/O ports, the parameters IIH and IIL include the off-state output current.

switching characteristics (see Figure 1)

					VCC = 4.5 V to 5.5 V,
					CL = 50 pF,
PARAMETER	FROM			TO	RL = 680 Ω,					UNIT
	(INPUT)			(OUTPUT)	T = MIN to MAX¶
						A
					SN74ALS641A			SN74ALS642A
					MIN	MAX		MIN	MAX
tPLH	A or B			B or A	5	25		10	30	ns
tPHL					3	18		5	22
tPLH					8	30		10	30	ns
	OE			A or B
tPHL					8	30		15	38
tPLH	DIR			A or B	8	32		10	30	ns
tPHL					8	32		15	38

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

POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

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