Philips N74ALS244A-1D, N74ALS244A-1DB, N74ALS244A-1N, N74ALS244AD, N74ALS244AN Datasheet

INTEGRATED CIRCUITS

74ALS244A/74ALS244A±1

Octal buffer (3±State)

Product specification	1991 Feb 08
IC05 Data Handbook

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Philips Semiconductors	Product specification
Octal buffer (3-State)	74ALS244A/74ALS244A-1

FEATURES

•Octal bus interface

•3-State buffer outputs sink 24mA and source 15mA

•The -1 version sinks 48mA

DESCRIPTION

The 74ALS244A is an octal buffer that is ideal for driving bus lines or buffer memory address registers. The outputs are all capable of sinking 24mA and sourcing up to 15mA, producing very good capacitive drive characteristics. The device features two output enables, OEa and OEb, each controlling four of the 3-State outputs.

The 74ALS244A-1 sinks 48 mA IOL if the VCC is limited to 5.0V ±0.25V.

	TYPICAL	TYPICAL
TYPE	PROPAGATION	SUPPLY CURRENT
	DELAY	(TOTAL)
74ALS244A	4.5ns	17mA
74ALS244A-1	4.5ns	17mA

PIN CONFIGURATION

			1	20		VCC
	OEa
	Ia0		2	19
						OEb
	Yb0		3	18	Ya0
	Ia1		4	17	Ib0
	Yb1		5	16	Ya1
	Ia2		6	15	Ib1
	Yb2		7	14	Ya2
	Ia3		8	13	Ib2
	Yb3		9	12	Ya3
GND			10	11	Ib3

SF00227

ORDERING INFORMATION

		ORDER CODE
			DRAWING
	DESCRIPTION	COMMERCIAL RANGE
		VCC = 5V ±10%,	NUMBER
		Tamb = 0°C to +70°C
	20-pin plastic DIP	74ALS244AN,	SOT146-1
		74ALS244A-1N
	20-pin plastic SOL	74ALS244AD,	SOT163-1
		744ALS244A-1D
	20-pin plastic	74ALS244ADB,	SOT339-1
	SSOP Type II	74ALS244A-1DB

INPUT AND OUTPUT LOADING AND FAN-OUT TABLE

	PINS										DESCRIPTION																74ALS (U.L.)								LOAD VALUE
																													HIGH/LOW						HIGH/LOW
	Ian, Ibn										Data inputs																1.0/1.0								20μA/0.1mA
											Output Enable inputs (active-Low)																1.0/1.0								20μA/0.1mA
	OEa, OEb
	Yan, Ybn										Data outputs																750/240								15mA/24mA
	Yan, Ybn										Data outputs (-1 version)																750/480								15mA/48mA
NOTE: One (1.0) ALS unit load is defined as: 20μA in the High state and 0.1mA in the Low state.
LOGIC SYMBOL																									IEC/IEEE SYMBOL
							2		4		6		8		17		15		13		11				1
																														EN1
																									19					EN2
							Ia0		Ia1		Ia2		Ia3		Ib0		Ib1		Ib2		Ib3				2										18
																														2D		1
1							OEa																		4										16
19							OEb																		6										14
							Ya0		Ya1 Ya2				Ya3		Yb0		Yb1		Yb2		Yb3				8							2			12
																									17										3
							18		16		14		12		3		5		7		9				15										5
																									13										7
VCC = Pin 20																									11										9
GND = Pin 10																							SF00228												SF00229

1991 Feb 08

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853±1277 01670

Philips Semiconductors	Product specification
Octal buffer (3-State)	74ALS244A/74ALS244A-1

LOGIC DIAGRAM

Ia0	2	18	Ya0	Ib0	17	3	Yb0
Ia1	4	16	Ya1	Ib1	15	5	Yb1
Ia2	6	14	Ya2	Ib2	13	7	Yb2
Ia3	8	12	Ya3	Ib3	11	9	Yb3
OEa	1			OEb	19

VCC = Pin 20

GND = Pin 10

SF00230

FUNCTION TABLE

				INPUTS						OUTPUTS
				Ia					Ib	Ya	Yb
		OEa				OEb
		L		L		L			L	L	L
		L		H		L			H	H	H
		H		X		H			X	Z	Z
H	=		High voltage level
L	=		Low voltage level
X	=		Don't care
Z	=		High impedance ªoffº state

ABSOLUTE MAXIMUM RATINGS

(Operation beyond the limit set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the operating free air temperature range.)

	SYMBOL	PARAMETER		RATING	UNIT
	VCC	Supply voltage		±0.5 to +7.0	V
	VIN	Input voltage		±0.5 to +7.0	V
	IIN	Input current		±30 to +5	mA
	VOUT	Voltage applied to output in High output state		±0.5 to VCC	V
	IOUT	Current applied to output in Low output state	All versions	48	mA
			-1 version	96	mA
	Tamb	Operating free-air temperature range		0 to +70	°C
	Tstg	Storage temperature range		±65 to +150	°C

RECOMMENDED OPERATING CONDITIONS

SYMBOL				LIMITS		UNIT
	PARAMETER
			MIN	NOM	MAX
VCC	Supply voltage		4.5	5.0	5.5	V
VIH	High-level input voltage		2.0			V
VIL	Low-level input voltage				0.8	V
IIK	Input clamp current				±18	mA
IOH	High-level output current				±15	mA
IOL	Low-level output current	All versions			24	mA
		-1 versions			481	mA
Tamb	Operating free-air temperature range		0		+70	°
						C

NOTES:

1. The 48mA limit applies only under the condition of VCC = 5.0V ± 5%.

1991 Feb 08

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