SGS Thomson Microelectronics 74ACT245 Datasheet



74ACT245

OCTAL BUS TRANSCEIVER (3-STATE)

■ HIGHSPEED:t

■

LOW POWER DISSIPATION: I

=8 µA (MAX.) at TA=25oC

CC

■

COMPATIBLEWITH TTLOUTPUTS V

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

IH

■ 50ΩTRANSMISSIONLINEOUTPUT DRIVE

=5.5ns(TYP.)atVCC=5V

PD

CAPABILITY

■ SYMMETRICALOUTPUTIMPEDANCE:

|I

|=IOL=24mA(MIN)

OH

■ BALANCEDPROPAGATIONDELAYS:

t

≅ t

PLH

PHL

■

OPERATINGVOLTAGERANGE: V

(OPR)= 4.5Vto 5.5V

CC

■ PINANDFUNCTION COMPATIBLEWITH

74SERIES245

■ IMPROVEDLATCH-UP IMMUNITY

DESCRIPTION

The ACT245 is an advanced CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C

2

MOS technology. It is ideal for low power applications mantaining high speed operation similar to equivalent Bipolar Schottky TTL. This IC is intended for two-way asynchronous communication between data buses and the

M

(Micro Package)

B

(PlasticPackage)

ORDER CODES :

74ACT245B

74ACT245M

(TSSOPPackage)

T

74ACT245T

direction of data trasmission is determined by DIR input. The enable input G can be used to disable the device so that the buses 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 THERMINAL IS FLOATING (HIGH IMPEDANCE STATE) IT IS REQUESTED TO FIX THE INPUT LEVEL BY MEANS OF EXTERNAL PULL DOWN OR PULL UP RESISTOR.

PIN CONNECTION AND IEC LOGICSYMBOLS

May 1999

1/9

74ACT245

INPUT AND OUTPUT EQUIVALENTCIRCUIT

TRUTH TABLE

INP UT FUNCTIO N OUT P UT

GDIRABUSBBUS

LLOUTPUTINPUTA=B

LHINPUTOUTPUTB=A

HXZZZ

X:”H” or”L” Z:Highimpedance

PIN DESCRIPTION

PI N No SYM BO L NAM E AN D F U NCTI O N

1 DIR Directional Control

2,3,4,5,

6,7,8,9

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

12, 11

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

A1toA8 Data Inputs/Outputs

B1toB8 Data Inputs/Outputs

Positive Supply Voltage

CC

ABSOLUTE MAXIMUM RATINGS

Symb o l Para met er Val u e Uni t

V

I

OK

I

orI

I

CC

T

AbsoluteMaximum Ratingsarethosevalues beyond whichdamageto thedevicemayoccur. Functionaloperationundertheseconditionisnotimplied.

Supply Voltage -0.5to+7 V

CC

DC Input Voltage -0.5toVCC+0.5 V

I

DC Output Voltage -0.5toVCC+0.5 V

O

DC Input Diode Current ±20 mA

IK

DC Output Diode Current ±20 mA DC Output Current ±50 mA

O

DC VCCor Ground Current

GND

Storage Temperature -65to+150

stg

Lead Temperature (10 sec) 300

L

400 mA

±

o

C

o

C

RECOMMENDED OPERATINGCONDITIONS

Symb o l Parameter Val u e Uni t

V

T

dt/dv Input Rise and Fall Time V

1)VINfrom0.8V to2.0V

Supply Voltage 4.5to5.5 V

CC

Input Voltage 0toV

I

Output Voltage 0toV

O

Operating Temperature: -40to+85

op

= 4.5 to 5.5V (note 1) 8 ns/V

CC

CC CC

V V

o

C

2/9

74ACT245

DC SPECIFICATIONS

Symbol Parameter Test Conditi ons Value Unit

T

V

CC

(V)

High Level Input Voltage 4.5 VO=0.1Vor

V

IH

5.5 2.0 1.5 2.0

Low Level Input Voltage 4.5 VO=0.1Vor

V

IL

5.5 1.5 0.8 0.8

High Level Output

V

OH

Voltage

4.5

5.5 I

V

4.5 I

5.5 I

Low Level Output

V

OL

Voltage

4.5

5.5 I

V

4.5 I

5.5 I

Input Leakage Current 5.5 VI=VCCorGND ±0.1 ±1 µA

I

3 State Output Leakage

I

OZ

5.5 VI=VIHorV

Current Max ICC/Input 5.5 VI=VCC-2.1V 0.6 1.5 mA

I

CCT

Quiescent Supply

I

CC

5.5 VI=VCCorGND 8 80 µA

-0.1V

V

CC

V

-0.1V

CC

IO=-50µA 4.4 4.49 4.4

(*)

=

I

or

IH

V

IL

(*)

I

or

IH

V

IL

=-50µA 5.4 5.49 5.4

O

=-24 mA 3.86 3.76

O

=-24 mA 4.86 4.76

O

IO=50µA 0.001 0.1 0.1

=

=50µA 0.001 0.1 0.1

O

=24mA 0.36 0.44

O

=24mA 0.36 0.44

O

IL

VO=VCCorGND

Current Dynamic Output Current

I

OLD

(note 1, 2)

I

OHD

1) Maximum test duration 2ms, one output loaded attime

2)Incident waveswitchingisguaranteed ontransmission lineswithimpedances aslowas50 Ω. (*)All outputs loaded.

5.5 V

=1.65V max 75 mA

OLD

V

=3.85V min -75 mA

OHD

=25oC -40 to 85oC

A

Min. Typ. Max. Min. Max.

2.0 1.5 2.0

1.5 0.8 0.8

±0.5 ±5 µA

V

3/9