Texas Instruments SN74ALS623A-1DW, SN74ALS623A-1DWR, SN74ALS623A-1N, SN74ALS623AN, SN74ALS623AN3 Datasheet

SN74ALS620A, SN74ALS621A, SN74ALS623A, SN74AS623

OCTAL BUS TRANSCEIVERS

SDAS226A ± DECEMBER 1982 ± REVISED JANUARY 1995

• Local Bus-Latch Capability				DW OR N PACKAGE
• Choice of True or Inverting Logic					(TOP VIEW)
• Package Options Include Plastic				OEAB		1	20			VCC
	Small-Outline (DW) Packages and Standard
				A1		2	19			OEBA
	Plastic (N) 300-mil DIPs			A2		3	18			B1
				A3		4	17			B2
	DEVICE	OUTPUT	LOGIC	A4		5	16			B3
				A5		6	15			B4
	SN74ALS620A	3 state	Inverting
	SN74ALS621A	Open collector	True	A6		7	14			B5
				A7		8	13			B6
	SN74ALS623A, SN74AS623	3 state	True
				A8		9	12			B7
description				GND		10	11			B8

These octal bus transceivers are designed for asynchronous two-way communication between data buses. The control-function implementation allows for maximum flexibility in timing.

These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending upon the logic levels at the output-enable (OEAB and OEBA) inputs.

The output-enable inputs disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability to store data by simultaneously enabling OEAB and OEBA. Each output reinforces its input in this transceiver configuration. When both OEAB and OEBA are enabled and all other data sources to the two sets of bus lines are in the high-impedance state, both sets of bus lines (16 total) remain at their last states. The 8-bit codes appearing on the two sets of buses are identical for the SN74ALS621A, SN74ALS623A, and SN74AS623 or complementary for the SN74ALS620A.

The -1 versions of the SN74ALS620A and SN74ALS621A are identical to the standard versions, except that the recommended maximum IOL is increased to 48 mA in the -1 versions.

The SN74ALS620A, SN74ALS621A, SN74ALS623A, and SN74AS623 are characterized for operation from 0°C to 70°C.

FUNCTION TABLE

	INPUTS							OPERATION
									SN74ALS621A
	OEBA	OEAB		SN74ALS620A					SN74ALS623A
									SN74AS623
	L	L						data to A bus	B data to A bus
						B
	H	H							A data to B bus
					A			data to B bus
	H	L						Isolation	Isolation
									B data to A bus,
	L	H		B			data to A bus,
						A data to B bus			A data to B bus

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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SN74ALS620A, SN74ALS621A, SN74ALS623A, SN74AS623

OCTAL BUS TRANSCEIVERS

SDAS226A ± DECEMBER 1982 ± REVISED JANUARY 1995

logic symbols²

SN74ALS620A

			19	EN1
	OEBA
			1
	OEAB			EN2

A1	2	18
	1	B1
	3	2
A2		17
		B2

	4		16
	A3		B3
	5		15
	A4		B4
	6		14
	A5		B5
	7		13
	A6		B6
	8		12
	A7		B7
	9		11
	A8		B8
	SN74ALS621A		SN74ALS623A, SN74AS623
	19		19
OEBA	EN1	OEBA	EN1
OEAB	1	OEAB	1
	EN2		EN2

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

1	18
	B1
	2
	17
	B2
	16
	B3
	15
	B4
	14
	B5
	13
	B6
	12
	B7
	11
	B8

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

2	POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

		SN74ALS620A, SN74ALS621A, SN74ALS623A, SN74AS623
					OCTAL BUS TRANSCEIVERS
				SDAS226A ± DECEMBER 1982 ± REVISED JANUARY 1995
logic diagrams (positive logic)
	SN74ALS620A				SN74ALS621A
OEBA	19		OEBA	19
OEAB	1		OEAB	1
					18
A1	2	18	A1	2	B1
		B1

To Seven Other Transceivers

To Seven Other Transceivers

SN74ALS623A, SN74AS623

19

OEBA

1

OEAB

A1	2	18
		B1

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . . . 7	V
I/O ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. . . . . . . . 5.5	V
Operating free-air temperature range, TA: SN74ALS620A, SN74ALS623A . . . . . . . . . . . . . . .	. . 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.

POST OFFICE BOX 655303 •DALLAS, TEXAS 75265

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