SGS Thomson Microelectronics 74VHCT244A Datasheet



74VHCT244A

OCTAL BUS BUFFER

WITH 3 STATE OUTPUTS (NON INVERTED)

■ HIGH SPEED:t

■ LOW POWERDISSIPATION:

=4 µA(MAX.) at TA=25oC

I

CC

■ COMPATIBLEWITHTTLOUTPUTS:

=2V(MIN),VIL=0.8V(MAX)

V

IH

■ POWERDOWN PROTECTIONON INPUTS&

=3.9ns (TYP.)at VCC=5V

PD

OUTPUTS

■ SYMMETRICALOUTPUTIMPEDANCE:

|I

|=IOL=8mA (MIN)

OH

■ BALANCEDPROPAGATIONDELAYS:

t

≅ t

PLH

PHL

■ OPERATINGVOLTAGERANGE:

(OPR)= 4.5Vto5.5V

V

CC

■ PINANDFUNCTIONCOMPATIBLEWITH

74SERIES244

■ IMPROVEDLATCH-UPIMMUNITY

■ LOWNOISEV

=0.9V(Max.)

OLP

DESCRIPTION

The 74VHCT244A is an advanced high speed
CMOS OCTAL BUS BUFFER (3-STATE)
fabricated with sub-micron silicon gate and
double-layermetal wiring C

2

MOS technology.

G output enable governsfour BUS BUFFERs.

M

(Micro Package)

(TSSOPPackage)

T

ORDERCODES :

74VHCT244AM 74VHCT244AT

This device is designed to be used with 3 state
memoryaddressdrivers, etc.
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
devicecan be usedto interface5Vto 3V.

All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

August 1999

1/8

74VCHT244A

INPUT EQUIVALENTCIRCUIT

TRUTH TABLE

INPUT OUTPU T

GAnYn

LLL
LHH

HXZ

X:”H” or”L”
Z:Highimpedance

ABSOLUTE MAXIMUM RATINGS

PIN DESCRIPTION

PI N No SYM BO L NAM E AN D F UNCTIO N

1 1G Output Enable Input
2,4,6,8 1A1to1A4 Data Inputs
9,7,5,3 2Y1to2Y4 Data Outputs

11,13,15,17 2A1to2A4 Data Inputs
18,16,14,12 1Y1to1Y4 Data Outputs

19 2G Output Enable Input
10 GND Ground (0V)
20 V

Positive Supply Voltage

CC

Symb o l Para met er Value U n i t

V

V
V
V

I

I

OK

I

orI

I

CC

T

T

AbsoluteMaximum Ratingsarethosevaluesbeyond whichdamagetothedevice mayoccur.Functionaloperationunder these condition isnotimplied.

1)OutputinOFFState

2)HighorLow State

Supply Voltage -0.5to+7.0 V

CC

DC Input Voltage -0.5to+7.0 V

I

DC Output Voltage (see note 1) -0.5to+7.0 V

O

DC Output Voltage (see note 2) -0.5toVCC+0.5 V

O

DC Input Diode Current -20 mA

IK

DC Output Diode Current
DC Output Current ±25 mA

O

DC VCCor Ground Current ±50 mA

GND

Storage Temperature -65to+150

stg

Lead Temperature (10 sec) 300

L

20 mA

±

o

C

o

C

RECOMMENDED OPERATING CONDITIONS

Symb o l Para met er Value Unit

V

V
V
V

T

dt/dv

1)OutputinOFFState

2)HighorLow State

3)V

from0.8Vto 2 V

IN

2/8

Supply Voltage 4.5to5.5 V

CC

Input Voltage 0to5.5 V

I

Output Voltage (see note 1) 0to5.5 V

O

Output Voltage (see note 2) 0toV

O

Operating Temperature -40to+85

op

Input Rise and Fall Time (see note 3) (V

=5.0±0.5V)

CC

CC

0to20 ns/V

V

o

C

74VHCT244A

DC SPECIFICATIONS

Symb o l Para met er Test Con ditio ns Val u e Uni t

T

V

CC

High Level Input

V

IH

(V)

4.5to5.5 2 2 V

Min. Typ. Max. Min. Max.

Voltage
Low Level Input

V

IL

4.5to5.5 0.8 0.8 V

Voltage
High Level Output

V

OH

Voltage
Low Level Output

V

OL

Voltage
High Impedance

I

OZ

Output Leakage

4.5 IO=-50µA4.44.5 4.4

4.5 I

=-8mA 3.94 3.8

O

4.5 IO=50µA 0.0 0.1 0.1

4.5 I

4.5to5.5 VI=VIHorV

=8mA 0.36 0.44

O

IL

VO=0Vto5.5V

Current
Input Leakage Current 0to5.5 VI=5.5VorGND ±0.1 ±1.0 µA

I

I

Quiescent Supply

I

CC

5.5 VI=VCCorGND 2 20

Current
Additional Worst Case

∆I

CC

Supply Current

5.5 One Inputat3.4V,
other inputat V

CC

or

GND

I

Output Leakage

OPD

0V

=5.5V 0.5 5.0

OUT

Current

=25oC -40 t o 85oC

A

±0.25 ±2.5 µA

1.35 1.5 mA

µ

µ

V

V

A

A

AC ELECTRICAL CHARACTERISTICS (Inputtr=tf=3 ns)

Symbol Parameter Test Co ndition Value Unit

t

Propagation Delay

PLH

t

Time

PHL

Output Disable Time 5.0

t

PLZ

t

PHZ

t

Output Enable Time 5.0

PZL

t

PZH

(*) Voltagerangeis 5.0V±0.5V

V

(V)

5.0

5.0

5.0

CC

C

L

(pF)

(*)
(*)

(*)
(*)
(*)

15 5.4 7.4 1.0 8.5
50 5.9 8.4 1.0 9.5
15 RL=1K
50 8.2 11.4 1.0 13.0
50 RL=1K

Min. Typ. Max. Min. Max.

Ω

Ω

=25oC -40 t o 85oC

T

A

7.7 10.4 1.0 12.0

8.8 11.4 1.0 13.0

ns

ns

ns

3/8

74VCHT244A

CAPACITIVE CHARACTERISTICS

Symb o l Para met er Test Con ditio ns Val u e Uni t

=25oC -40 t o 85oC

T

A

Min. Typ. Max. Min. Max.

Input Capacitance 4 10 10

C

IN

C

Output Capacitance 9

OUT

Power Dissipation

C

PD

18 pF

Capacitance (note 1)

1)CPDisdefinedasthevalueoftheIC’sinternalequivalentcapacitance whichiscalculated fromtheoperatingcurrentconsumption withoutload.(Referto
TestCircuit).Average operating currentcanbeobtainedbythefollowingequation.I

(opr)=CPD• VCC• fIN+ICC/48(perGate)

CC

DYNAMICSWITCHING CHARACTERISTICS

Symb o l Para met er Test Con ditio ns Val u e Uni t

T

V

CC

(V)

V
V

Dynamic Low Voltage

OLP

Quiet Output (note 1, 2)

OLV

Dynamic High Voltage

V

IHD

5.0

5.0 2.0

=50pF

C

L

Min. Typ. Max. Min. Max.

Input (note 1, 3)
Dynamic Low Voltage

V

ILD

5.0 0.8

Input (note 1, 3)

1)Worstcasepackage.

2)Max numberofoutputsdefinedas (n).Datainputsaredriven0Vto5.0V,(n-1)outputs switchingandoneoutputatGND.

3)Max numberofdatainputs (n)switching.(n-1)switching0Vto5.0V.Inputsundertest switching: 5.0Vtothreshold (V

=25oC -40 t o 85oC

A

0.9 1.1

-1.1 -0.9

),0Vtothreshold(V

ILD

),f=1MHz.

IHD

pF
pF

V

TESTCIRCUIT

TEST SWITCH

t

PLH,tPHL

t

PZL,tPLZ

t

PZH,tPHZ

CL= 15/50pFor equivalent (includes jigand probe capacitance)

=1KΩorequivalent

R

L=R1

R

ofpulsegenerator (typically50Ω)

T=ZOUT

Open

V

CC

GND

4/8

74VHCT244A

WAVEFORM 1: PROPAGATIONDELAYS

(f=1MHz;50% dutycycle)

WAVEFORM 2: OUTPUTENABLE AND DISABLETIME(f=1MHz; 50% dutycycle)

5/8

74VCHT244A

SO-20 MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.65 0.104
a1 0.10 0.20 0.004 0.007
a2 2.45 0.096

b 0.35 0.49 0.013 0.019
b1 0.23 0.32 0.009 0.012

C 0.50 0.020

c1 45 (typ.)

D 12.60 13.00 0.496 0.512

E 10.00 10.65 0.393 0.419

e 1.27 0.050
e3 11.43 0.450

F 7.40 7.60 0.291 0.299

L 0.50 1.27 0.19 0.050

M 0.75 0.029

S 8 (max.)

mm inch

6/8

P013L

TSSOP20 MECHANICAL DATA

74VHCT244A

DIM.

mm inch

MIN. TYP. MAX. MIN. TYP. MAX.

A 1.1 0.433

A1 0.05 0.10 0.15 0.002 0.004 0.006

A2 0.85 0.9 0.95 0.335 0.354 0.374

b 0.19 0.30 0.0075 0.0118

c 0.09 0.2 0.0035 0.0079

D 6.4 6.5 6.6 0.252 0.256 0.260

E 6.25 6.4 6.5 0.246 0.252 0.256

E1 4.3 4.4 4.48 0.169 0.173 0.176

e 0.65 BSC 0.0256 BSC

K0

o

o

4

o

8

o

0

o

4

L 0.50 0.60 0.70 0.020 0.024 0.028

o

8

A2

A

A1

PIN 1 IDENTIFICATION

b

e

K

c

L

E

D

E1

1

7/8

74VCHT244A

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of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is
granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in thispublication are
subject tochange without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products
are notauthorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.

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