SGS Thomson Microelectronics 74VHCT245A Datasheet



■ HIGHSPEED:t

■ LOW POWER DISSIPATION:

=4 µA (MAX.)at TA=25oC

I

CC

■ COMPATIBLEWITHTTLOUTPUTS:

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

V

IH

■ POWERDOWNPROTECTIONON INPUTS&

=4.5ns(TYP.)atVCC=5V

PD

OUTPUTS

■ SYMMETRICALOUTPUTIMPEDANCE:

|I

|=IOL=8 mA(MIN)

OH

■ BALANCEDPROPAGATIONDELAYS:

t

≅ t

PLH

PHL

■ OPERATINGVOLTAGERANGE:

(OPR)= 4.5Vto 5.5V

V

CC

■ PINANDFUNCTIONCOMPATIBLEWITH

74SERIES245

■ IMPROVEDLATCH-UP IMMUNITY

■ LOWNOISE:V

= 0.9V(Max.)

OLP

DESCRIPTION

The 74VHCT245A is an advanced high-speed
CMOS OCTAL BUS TRANSCEIVER (3-STATE)
fabricated with sub-micron silicon gate and
double-layermetal wiring C

2

MOS technology.

This IC is intended for two-way asynchronous
communication between data busses; the
direction of data trasmission is determinedby the

74VHCT245A

OCTAL BUS

TRANSCEIVER(3-STATE)

PRELIMINARY DATA

M

(Micro Package)

(TSSOPPackage)

ORDERCODES :

74VHCT245AM 74VHCT245AT

level of the DIR input. The enable input G can be
used to disable the device so that the busses are
effectivelyisolated.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.

IT IS PROHIBITED TO APPLY A SIGNAL TO A
TERMINAL WHEN IT IS IN OUTPUT MODE
AND WHEN A BUS TERMINAL IS FLOATING
(HIGH IMPEDANCE STATE) IT IS REQUESTED
TO FIX THE INPUT LEVEL BY MEANS OF
EXTERNAL PULL DOWN OR PULL UP
RESISTOR.

T

PIN CONNECTION AND IEC LOGICSYMBOLS

August 1999

1/9

74VHCT245A

INPUT/OUTPUT EQUIVALENTCIRCUIT

INPUT EQUIVALENTCIRCUIT PIN DESCRIPTION

PI N No SYM BO L NAM E AND F U NCTIO N

1 DIR Directional Control

2, 3, 4, 5,

6, 7, 8,9

18, 17, 16,
15, 14, 13,

12, 11

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

A1 to A8 Data Inputs/Outputs

B1 to B8 Data Inputs/Outputs

CC

Positive Supply Voltage

TRUTH TABLE

GDIRABUSBBUS

L L OUTPUT INPUT A = B
L H INPUT OUTPUT B = A

HXZZZ

X:”H” or”L”
Z:Highimpedance

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INP UT FUNCTI O N OUT P UT

74VHCT245A

ABSOLUTE MAXIMUMRATINGS

Symb o l Para met er Val u e Uni t

V

V
V
V

I

I

OK

I

or I

I

CC

T

T

AbsoluteMaximumRatingsarethosevalues beyond whichdamagetothedevicemayoccur.Functionaloperationunderthesecondition isnotimplied.

1)Outputin OffState

2)HighorLowState.I

RECOMMENDEDOPERATINGCONDITIONS

Symb o l Para met er Value Un it

V

V

V
V

T

dt/dv

1)Outputin OffState

2)HighorLowState.I
from0.8to2V

3)V

IN

Supply Voltage -0.5 to +7.0 V

CC

DC Input Voltage (DIR, G) -0.5 to +7.0 V

I

DC Bus I/O Voltage (see note 1) -0.5 to +7.0 V

I/O

DC Bus I/O Voltage (see note 2) -0.5 to VCC+ 0.5 V

I/O

DC Input Diode Current - 20 mA

IK

DC Output Diode Current
DC Output Current

O

DC VCCor Ground Current ± 75 mA

GND

Storage Temperature -65 to +150

stg

Lead Temperature (10 sec) 300

L

absolutemaximum ratingmustbe observed.

O

Supply Voltage 4.5 to 5.5 V

CC

Input Voltage (DIR, G) 0 to 5.5 V

I

Bus I/O Voltage (see note 1) 0 to 5.5 V

I/O

Bus I/O Voltage (see note 2) 0 to V

I/O

Operating Temperature -40 to +85

op

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

absolutemaximum ratingmustbe observed.

O

=5.0±0.5V)

CC

20 mA

±

25 mA

±

CC

0 to 20 ns/V

o

C

o

C

V

o

C

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