Datasheet 74ACT257 Datasheet (SGS Thomson Microelectronics)

74ACT257

QUAD 2 CHANNEL MULTIPLEXER (3-STATE)

■ HIGH SPEED: t

■ LOW POWE RDISSIPATION:

=8 µA (MAX.)at TA=25oC

I

CC

■ COMPATIBLEWITHTTL OUTPUTS

V

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

IH

■ 50Ω TRANSMISSIONLINEDRIVING

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

PD

CAPABILITY

■ SYMMETRICALOUTPUTIMPEDANCE:

|I

|=IOL=24mA(MIN)

OH

■ BALANCEDPROPAGATIONDELAYS:

t

≅ t

PLH

PHL

■ OPERATINGVOLTAGE RANGE:

V

(OPR)= 4.5Vto 5.5V

CC

■ PINAND FUNCTION COMPATIBLE WITH

74 SERIES257

■ IMPROVED LATCH-UP IMMUNITY

DESCRIPTION

The ACT257 is an advanced high-speed CMOS
QUAD 2 CHANNEL MULTIPLEXER (3-STATE)
fabricated with sub-micron silicon gate and
double-layermetal wiring C

2

MOS technology.

It is ideal for low power applications mantaining
high speed operation similar to equivalentBipolar
SchottkyTTL.

These IC’s are composed of an independent 2
channel multiplexer with common SELECT and

B

(Plastic Package)

(Micro Package)

M

ORDERCODES :

74ACT257B 74ACT257M

ENABLEINPUT.
TheAC257 is a noninverting multiplexer.
When the ENABLE INPUT is held ”High” outputs

of both IC’s become high impedance state. If
SELECT INPUT is held ”Low”, ”A” data is
selected, when SELECT INPUT is ”High”, ”B”
datais closen.

The device is designed to interface directly High
Speed CMOS systems with TTL, NMOS and
CMOSoutput voltage levels.

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

PINCONNECTION AND IEC LOGIC SYMBOLS

April 1997

1/10

74ACT257

INPUTAND OUTPUTEQUIVALENTCIRCUIT

TRUTH TABLE

INPUTS OUTPUTS

OESELECTABY

HXXXZ

LLLXL
LLHXH
LHXLL
LHXHH

X = DON’T CARE Z =HIGH IMPEDANCE

PIN DESCRIPTION

PI N No SYM B O L NAME A ND FUNCTI ON

1 SELECT Common Data Select Input
2, 5, 14, 11 1A to 4A Data Input From Source A
3, 6, 13, 10 1B to 4B Data Inputs from Source B

4, 7, 12, 9 1Y to 4Y 3 State Multiplexer Outputs

15 OE 3 State Output Enable

Inputs (Active LOW)

8 GND Ground (0V)

16 V

CC

Positive Supply Voltage

LOGICDIAGRAMS

This logic diagram has not be used to estimate propagation delays

2/10

74ACT257

ABSOLUTE MAXIMUMRATINGS

Symb o l Parame t er Val u e Uni t

V

V

V

I

I

OK

I

orI

I

CC

T

T

Absolute Maximum Ratings are those values beyond which damage to thedevice may occur. Functional operation under these condition is not implied.

RECOMMENDEDOPERATINGCONDITIONS

Symbol Parameter Valu e Unit

V

V

V

T

dt/dv Input Rise and Fall Time V

1) VINfrom0.8Vto2.0V

Supply Voltage -0.5 to +7 V

CC

DC Input Voltage -0.5 to VCC+ 0.5 V

I

DC Output Voltage -0.5 to VCC+ 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 ± 200 mA

GND

Storage Temperature -65 to +150

stg

Lead Temperature (10 sec) 300

L

Supply Voltage 4.5 to 5.5 V

CC

Input Voltage 0 to V

I

Output Voltage 0 to V

O

Operating Temperature: -40 to +85

op

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

CC

CC
CC

o

C

o

C

V
V

o

C

3/10

74ACT257

DC SPECIFICATIONS

Symbol Parameter Test Condition s Value Unit

T

V

CC

(V)

High Level Input Voltage 4.5 VO= 0.1 V or

V

IH

5.5 2.0 1.5 2.0

Low Level Input Voltage 4.5 VO= 0.1 V or

V

IL

5.5 1.5 0.8 0.8

High Level Output

V

OH

Voltage

4.5

5.5 I

4.5 I

5.5 I

Low Level Output

V

OL

Voltage

4.5

5.5 I

4.5 I

5.5 I

Input Leakage Current

I

I

3 State Output Leakage

I

OZ

5.5

5.5 VI=VIHor V

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

I

CCT

Quiescent Supply

I

CC

5.5 VI=VCCor GND 8 80 µA

V

- 0.1 V

CC

- 0.1 V

V

CC

IO=-50 µA 4.4 4.49 4.4

(*)

=

V

I

V

IH

V

IL

(*)

V

I

V

IH

V

IL

=-50 µA 5.4 5.49 5.4

O

or

=-24 mA 3.86 3.76

O

=-24 mA 4.86 4.76

O

IO=50 µA 0.001 0.1 0.1

=

=50 mA 0.001 0.1 0.1

O

or

=24 mA 0.36 0.44

O

=24 mA 0.36 0.44

O

VI=VCCor GND ±0.1 ±1 µA

VO=VCCor GND

IL

=25oC-40to85

A

Min. T yp . Max. Min . Max.

2.0 1.5 2.0

1.5 0.8 0.8

±0.5 ±5 µA

o

C

Current
Dynamic Output Current

I

OLD

(note 1, 2)

I

OHD

1) Maximum test duration 2ms, one output loaded at time

2) Incident wave switching is guaranteed on transmission lines with impedances as lowas 50 Ω.
(*)All outputs loaded.

5.5 V

= 1.65 V max 75 mA

OLD

V

= 3.85 V min -75 mA

OHD

V

V

V

V

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AC ELECTRICAL CHARACTERISTICS (CL= 50 pF, RL=500 Ω, Input tr=tf=3ns)

74ACT257

Symbol Parameter Test Cond ition Value Unit

o

C

t

Propagation Delay Time

PLH

t

A, B to Y

PHL

Propagation Delay Time

t

PLH

t

SEL to Y

PHL

Output Enable Time 5.0

t

PZL

t

PZH

t

Output Disable Time 5.0

PLZ

t

PHZ

(*) Voltagerangeis5V± 0.5V

V

(V)

5.0

5.0

CC

T

=25oC-40to85

A

Min. T yp . Max. Min . Max.

(*)

(*)

(*)

(*)

5.0 7.0 8.0 ns

6.0 9.0 10.0 ns

5.0 8.0 9.0 ns

6.0 9.0 10.0 ns

CAPACITIVE CHARACTERISTICS

Symbol Parameter Test Condition s Value Unit

T

V

CC

(V)

Input Capacitance

C

IN

C

Input Capacitance

OUT

Power Dissipation

C

PD

5.0

5.0

5.0 31 pF

=25oC-40to85

A

Min. T yp . Max. Min . Max.

4
8

Capacitance (note 1)

1) CPDis defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without load. (Refer to
Test Circuit). Average operating current can be obtained by the following equation. I

(opr) = CPD• VCC•fIN+ICC/n (percircuit)

CC

o

C

pF
pF

TEST CIRCUIT

TEST SWITC H

t

PLH,tPHL

t

PZL,tPLZ

t

PZH,tPHZ

CL= 50 pF or equivalent (includes jig and probe capa citance)

= 500Ω or equivalent

R

L=R1

R

of pulse generator (typically 50Ω)

T=ZOUT

Open

2V

CC

Open

5/10

74ACT257

WAVEFORM 1: PROPAGATION DELAYS FOR INVERTINGCONDITIONS (f=1MHz;50% duty cycle)

WAVEFORM 2: PROPAGATION DELAYS FOR NON-INVERTING CONDITIONS (f=1MHz; 50% duty

cycle)

6/10

WAVEFORM 3: OUTPUTENABLE AND DISABLE TIME (f=1MHz;50% duty cycle)

74ACT257

7/10

74ACT257

Plastic DIP16 (0.25)MECHANICAL DATA

DIM.

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

a1 0.51 0.020

B 0.77 1.65 0.030 0.065
b 0.5 0.020

b1 0.25 0.010

D 20 0.787
E 8.5 0.335
e 2.54 0.100

e3 17.78 0.700

F 7.1 0.280

I 5.1 0.201
L 3.3 0.130
Z 1.27 0.050

mm inch

8/10

P001C

SO16 MECHANICAL DATA

74ACT257

DIM.

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

A 1.75 0.068

a1 0.1 0.2 0.004 0.007
a2 1.65 0.064

b 0.35 0.46 0.013 0.018

b1 0.19 0.25 0.007 0.010

C 0.5 0.019

c1 45 (typ.)

D 9.8 10 0.385 0.393
E 5.8 6.2 0.228 0.244
e 1.27 0.050

e3 8.89 0.350

F 3.8 4.0 0.149 0.157
G 4.6 5.3 0.181 0.208
L 0.5 1.27 0.019 0.050

M 0.62 0.024

S 8 (max.)

mm inch

P013H

9/10

74ACT257

Information furnished is believed to be accurate and reliable. However, SGS-THOMSONMicroelectronics assumes no responsability for the
consequencesof use of such informationnor for any infringement of patents or otherrights of third parties whichmay results from its use. No
licenseis grantedby implicationor otherwise underany patentor patent rights of SGS-THOMSON Microelectronics.Specificationsmentioned
in this publicationare subject to change without notice.This publication supersedes and replaces all informationpreviously supplied.
SGS-THOMSONMicroelectronics products are notauthorized for useascriticalcomponents in life supportdevices or systems withoutexpress
writtenapproval of SGS-THOMSONMicroelectonics.

 1997 SGS-THOMSONMicroelectronics - Printedin Italy - All Rights Reserved

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