MOTOROLA SN74LS240DW, SN74LS240ML2, SN74LS240MR1, SN74LS240MR2, SN74LS240N Datasheet

SN74LS240 SN74LS244

Octal Buffer/Line Driver with 3-State Outputs

The SN74LS240 and SN74LS244 are Octal Buffers and Line Drivers designed to be employed as memory address drivers, clock drivers and bus-oriented transmitters/receivers which provide improved PC board density.

•Hysteresis at Inputs to Improve Noise Margins

•3-State Outputs Drive Bus Lines or Buffer Memory Address Registers

•Input Clamp Diodes Limit High-Speed Termination Effects

GUARANTEED OPERATING RANGES

Symbol	Parameter	Min	Typ	Max	Unit
VCC	Supply Voltage	4.75	5.0	5.25	V
TA	Operating Ambient	0	25	70	°C
	Temperature Range
IOH	Output Current ± High			± 3.0	mA
				± 15	mA
IOL	Output Current ± Low			24	mA

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LOW

POWER

SCHOTTKY

20

1

PLASTIC

N SUFFIX

CASE 738

20

1

SOIC

DW SUFFIX

CASE 751D

ORDERING INFORMATION

Device	Package	Shipping
SN74LS240N	16 Pin DIP	1440 Units/Box
SN74LS240DW	16 Pin	2500/Tape & Reel
SN74LS244N	16 Pin DIP	1440 Units/Box
SN74LS244DW	16 Pin	2500/Tape & Reel

Semiconductor Components Industries, LLC, 1999	1	Publication Order Number:
December, 1999 ± Rev. 6		SN74LS240/D

SN74LS240 SN74LS244

LOGIC AND CONNECTION DIAGRAMS DIP (TOP VIEW)

SN74LS240

VCC 2G 1Y1 2A4 1Y2 2A3 1Y3 2A2 1Y4 2A1 20 19 18 17 16 15 14 13 12 11

1				2		3		4		5		6		7		8		9		10
				1A1		2Y4		1A2		2Y3		1A3		2Y2		1A4		2Y1		GND
1G

SN74LS244

																		1Y4		2A1
VCC		2G				1Y1		2A4		1Y2		2A3		1Y3		2A2
20		19				18		17		16		15		14		13		12		11

1				2		3		4		5		6		7		8		9		10
				1A1		2Y4		1A2		2Y3		1A3		2Y2		1A4		2Y1		GND
1G

TRUTH TABLES

SN74LS240

SN74LS244

		INPUTS					OUTPUT
						D
1G,		2G
		L				L	H
		L				H	L
	H					X	(Z)

		INPUTS					OUTPUT
						D
1G,		2G
		L				L	L
		L				H	H
	H					X	(Z)

H = HIGH Voltage Level

L = LOW Voltage Level

X = Immaterial

Z = HIGH Impedance

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SN74LS240 SN74LS244

DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)

					Limits
Symbol	Parameter			Min	Typ	Max	Unit		Test Conditions
VIH	Input HIGH Voltage			2.0			V	Guaranteed Input HIGH Voltage for
								All Inputs
VIL	Input LOW Voltage					0.8	V	Guaranteed Input LOW Voltage for
								All Inputs
VT+±VT±	Hysteresis			0.2	0.4		V	VCC = MIN
VIK	Input Clamp Diode Voltage				± 0.65	± 1.5	V	VCC = MIN, IIN = ± 18 mA
VOH	Output HIGH Voltage			2.4	3.4		V	VCC = MIN, IOH = ± 3.0 mA
				2.0			V	VCC = MIN, IOH = MAX
					0.25	0.4	V	I = 12 mA		VCC = VCC MIN,
VOL	Output LOW Voltage							OL		VIN = VIL or VIH
					0.35	0.5	V	IOL = 24 mA
										per Truth Table
IOZH	Output Off Current HIGH					20	μA	VCC = MAX, VOUT = 2.7 V
IOZL	Output Off Current LOW					± 20	μA	VCC = MAX, VOUT = 0.4 V
IIH	Input HIGH Current					20	μA	VCC = MAX, VIN = 2.7 V
						0.1	mA	VCC = MAX, VIN = 7.0 V
IIL	Input LOW Current					± 0.2	mA	VCC = MAX, VIN = 0.4 V
IOS	Output Short Circuit Current (Note 1)			± 40		± 225	mA	VCC = MAX
	Power Supply Current
	Total, Output HIGH					27
	Total, Output LOW		LS240			44
ICC							mA	VCC = MAX
			LS244			46
	Total at HIGH Z		LS240			50
			LS244			54

Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.

AC CHARACTERISTICS (TA = 25°C, VCC = 5.0 V)

			Limits
Symbol	Parameter				Unit	Test Conditions
		Min	Typ	Max
tPLH	Propagation Delay, Data to Output		9.0	14	ns
tPHL	LS240		12	18
tPLH	Propagation Delay, Data to Output		12	18	ns	CL = 45 pF,
tPHL	LS244		12	18		RL = 667 Ω
tPZH	Output Enable Time to HIGH Level		15	23	ns
tPZL	Output Enable Time to LOW Level		20	30	ns
tPLZ	Output Disable Time from LOW Level		15	25	ns	CL = 5.0 pF,
tPHZ	Output Disable Time from HIGH Level		10	18	ns	RL = 667 Ω

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