Fairchild Semiconductor 74VHCT244ASJX, 74VHCT244ASJ, 74VHCT244AN, 74VHCT244AMX, 74VHCT244AMTCX Datasheet

March 1997

Revised March 1999

74VHCT244A

Octal Buffer/Line Driver with 3-STATE Outputs

General Description

The VHCT244A is an advanced high speed CMOS octal bus transceiver fabricated with silicon gate CMOS technology. It achieves high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. The VHCT244A is a non-inverting 3- STATE buffer having two active-LOW output enables. This device is designed to be used as 3-STATE memory address drivers, clock drivers, and bus oriented transmitter/ receivers.

Protection circuits ensure that 0V to 7V can be applied to the input and output (Note 1) pins without regard to the supply voltage. These circuits prevent device destruction

due to mismatched supply and input/output voltages. This device can be used to interface 5V to 3V systems and two supply systems such as battery back up.

Note 1: Outputs in OFF-State

Features

■High Speed: tPD = 5.9 ns (typ) at VCC = 5V

■Power down protection is provided on inputs and outputs

■Low power dissipation: ICC = 4 μA (max) @ TA = 25°C

■Pin and function compatible with 74HCT244

Ordering Code:

Order Number	Package Number	Package Description
74VHCT244AM	M20B	20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
74VHCT244ASJ	M20D	20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74VHCT244AMTC	MTC20	20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
74VHCT244AN	N20A	20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Logic Symbol

Connection Diagram

Pin Descriptions

	Pin Names				Description
		1,		2	3-STATE Output Enable Inputs
	OE		OE
I0–I7					Inputs
O0–O7					3-STATE Outputs

Outputs STATE-3 with Driver Buffer/Line Octal 74VHCT244A

© 1999 Fairchild Semiconductor Corporation

DS500003.prf

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74VHCT244A

Truth Tables

			Inputs		Outputs
OE1				In	(Pins 12, 14, 16, 18)
	L			L	L
	L			H	H
	H			X	Z
			Inputs		Outputs
OE2				In	(Pins 3, 5, 7, 9)
	L			L	L
	L			H	H
	H			X	Z

H = HIGH Voltage Level

L = LOW Voltage Level

I = Immaterial

Z = High Impedance

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2

Absolute Maximum Ratings(Note 2)

Supply Voltage (V			)	−0.5V to +7.0V
		CC		−0.5V to +7.0V
DC Input Voltage (V			)
			IN
DC Output Voltage (VOUT)				−0.5V to VCC + 0.5V
(Note 3)
(Note 4)				−0.5V to +7.0V
Input Diode Current (IIK)				−20 mA
Output Diode Current (IOK) (Note 5)				±20 mA
DC Output Current (IOUT)				±25 mA
DC V	/GND Current (I )			±75 mA
	CC		CC	−65°C to +150°C
Storage Temperature (TSTG)
Lead Temperature (TL)				260°C
(Soldering, 10 seconds)

Recommended Operating

Conditions (Note 6)

Supply Voltage (V	)		4.5V to +5.5V
CC			0V to +5.5V
Input Voltage (V )
IN
Output Voltage (VOUT)
(Note 3)			0V to VCC
(Note 4)			0V to +5.5V
Operating Temperature (T		)	−40°C to +85°C
		OPR
Input Rise and Fall Time (tr, tf)
VCC = 5.0V ± 0.5V			0 ns/V 20 ns/V

Note 2: Absolute Maximum Ratings are values beyond which the device may be damaged or have its useful life impaired. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output/input loading variables. Fairchild does not recommend operation outside databook specifications.

Note 3: HIGH or LOW state. IOUT absolute maximum rating must be observed.

Note 4: When outputs are in OFF-STATE or when VCC = OV.

Note 5: VOUT < GND, VOUT > VCC (Outputs Active).

Note 6: Unused inputs must be held HIGH or LOW. They may not float.

DC Electrical Characteristics

	Symbol	Parameter	V CC		TA = 25°C		TA = −40°C to +85°C		Units	Conditions
			(V)	Min	Typ	Max	Min	Max
	VIH	HIGH Level	4.5	2.0			2.0		V
		Input Voltage	5.5	2.0			2.0
	VIL	LOW Level	4.5			0.8		0.8	V
		Input Voltage	5.5			0.8		0.8
	VOH	HIGH Level	4.5	4.40	4.50		4.40		V	VIN = VIH	IOH = −50 μA
		Output Voltage		3.94			3.80		V	or VIL	IOH = −8 mA
	VOL	LOW Level	4.5		0.0	0.1		0.1	V	VIN = VIH	IOL = 50 μA
		Output Voltage				0.36		0.44	V	or VIL	IOL = 8 mA
	IOZ	3-STATE Output	5.5			±0.25		±2.5	μA	VIN = VIH or	VIL
		Off-State Current								VOUT = VCC or GND
	IIN	Input Leakage	0–5.5			±0.1		±1.0	μA	VIN = 5.5V or GND
		Current
	ICC	Quiescent Supply	5.5			4.0		40.0	μA	VIN = VCC or GND
		Current
	ICCT	Maximum ICC/Input	5.5			1.35		1.50	mA	VIN = 3.4V
										Other Input = VCC or GND
	IOFF	Output Leakage Current	0.0			0.5		5.0	μA	VOUT = 5.5V
		(Power Down State)

74VHCT244A

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