Datasheet M74HC257 Datasheet (ST)

M74HC257

QUAD 2 CHANNEL MULTIPLEXER (3-STATE)

■ HIGH SPEED :

t

= 11 ns (TYP.) at VCC = 6V

PD

■ LOW POWER DISSIPATION:

I

=4µA(MAX.) at TA=25°C

CC

■ HIGH NOISE IMMUNITY:

V

= V

NIH

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

| = IOL = 6mA (MIN)

OH

■ BALANCED PROPAGATION DELAYS:

t

≅ t

PLH

■ WIDE OPERATING VOLTAGE RANGE:

V

(OPR) = 2V to 6V

CC

■ PIN AND FUNCTION COMPATIBLE WITH

= 28 % VCC (MIN.)

NIL

PHL

74 SERIES 257

DESCRIPTION

The M74HC257 is an hi gh speed CM O S Q UA D 2
CHANNEL MULTIPLEXER (3-STATE) fabricated
with silicon gate C

2

MOS technology.
This IC is composed of an independent 2-channel
multiplexer with common SELECT and ENABLE
(OE

) input.

The M74HC257 is a non-inverting multiplexer.

TSSOPDIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP M74HC257B1R

SOP M74HC257M1R M74HC257RM13TR

TSSOP M74HC257TTR

When the ENABLE input is held "High", outputs of
the IC become in a High-Impedance state. If
SELECT input is held low, "A" data is selected,
when SELECT is high , "B" data is chosen.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

1/11August 2001

M74HC257

INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

1 SELECT

2, 5, 14, 11 1A to 4A Data Input From Source A
3, 6, 13, 10 1B to 4B Data Input From Source B

4, 7, 12, 9 1Y to 4Y

15 OE

8 GND Ground (0V)

16 Vcc Positive Supply Voltage

TRUTH TABLE

INPUTS OUTPUT

Common Data Select
Input

3 State Multiplexer
Outputs

3 State Output Enable
Inputs (Active Low)

OE

HXXXZ

LLLXL
LLHXH
LHXLL
LHXHH

X : Don’t Care
Z : High Impedance

LOGIC DIAGRAM

SELECT A B Y

This log i c diagram has not be used to esti m ate propagation delays

2/11

M74HC257

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

V

V

I

I

OK

I

I

or I

CC

P

T

T

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
(*) 500mW at 65

RECOMMENDED OPERATING CONDITIONS

Symbol Parameter Value Unit

V

V

V

T

t

r

Supply Voltage

CC

DC Input Voltage -0.5 to VCC + 0.5

I

DC Output Voltage -0.5 to VCC + 0.5

O

DC Input Diode Current

IK

DC Output Diode Current
DC Output Current

O

DC VCC or Ground Current

GND

Power Dissipation

D

Storage Temperature

stg

Lead Temperature (10 sec)

L

°C; derate to 300mW by 10mW/°C from 65°C to 85°C

Supply Voltage

CC

Input Voltage 0 to V

I

Output Voltage 0 to V

O

Operating Temperature

op

Input Rise and Fall Time VCC = 2.0V

, t

f

V
V

CC
CC

= 4.5V
= 6.0V

-0.5 to +7 V

± 20 mA
± 20 mA
± 35 mA
± 70 mA

500(*) mW

-65 to +150 °C

300 °C

2 to 6 V

CC
CC

-55 to 125 °C
0 to 1000 ns

0 to 500 ns
0 to 400 ns

V
V

V
V

3/11

M74HC257

DC SPECIFICATIONS

Symbol Parameter

V

V

V

V

I

I

High Level Input

IH

Voltage

Low Level Input

IL

Voltage

High Level Output

OH

Voltage

Low Level Output

OL

Voltage

I

Input Leakage

I

Current
High Impedance

OZ

Output Leakage
Current

Quiescent Supply

CC

Current

Test Condition Value

V

(V)

CC

= 25°C

A

Min. Typ. Max. Min. Max. Min. Max.

-40 to 85°C -55 to 125°C

T

2.0 1.5 1.5 1.5

6.0 4.2 4.2 4.2

2.0 0.5 0.5 0.5

6.0 1.8 1.8 1.8

2.0

4.5

6.0

4.5

6.0

2.0

4.5

6.0

4.5

6.0

6.0

6.0

6.0

IO=-20 µA
I

=-20 µA

O

I

=-20 µA

O

I

=-6.0 mA

O

I

=-7.8 mA

O

IO=20 µA
I

=20 µA

O

I

=20 µA

O

I

=6.0 mA

O

I

=7.8 mA

O

= VCC or GND

V

I

= VIH or V

V

I

IL

VO = VCC or GND

= VCC or GND

V

I

1.9 2.0 1.9 1.9

4.4 4.5 4.4 4.4

5.9 6.0 5.9 5.9

4.18 4.31 4.13 4.10

5.68 5.8 5.63 5.60

0.0 0.1 0.1 0.1

0.0 0.1 0.1 0.1

0.0 0.1 0.1 0.1

0.17 0.26 0.33 0.40

0.18 0.26 0.33 0.40

± 0.1 ± 1 ± 1 µA

± 0.5 ± 5 ± 10 µA

44080µA

Unit

V4.5 3.15 3.15 3.15

V4.5 1.35 1.35 1.35

V

V

4/11

AC ELECTRICAL CHARACTERISTICS (CL = 50 pF, Input tr = tf = 6ns)

Test Condition Value

T

Symbol Parameter

t

TLH tTHL

t

PLH tPHL

Output Transition
Time

Propagation Delay
Time

(A, B - Y)

t

PLH tPHL

Propagation Delay
Time

(SELECT - Y)

t

PZL tPZH

High Impedance
Output Enable
Time

t

PLZ tPHZ

High Impedance
Output Disable
Time

V

CC

(V)

2.0
50

6.0 6101315

2.0
50

6.0 11 17 21 26

2.0

150

6.0 15 24 30 36

2.0
50

6.0 11 17 21 26

2.0

150

6.0 15 24 30 36

2.0

R

50

= 1 KΩ

L

6.0 10 19 24 28

2.0

150

L

= 1 KΩ

R

6.0 14 26 32 38

2.0

R

50

= 1 KΩ

L

6.0 13 24 30 36

= 25°C

A

Min. Typ. Max. Min. Max. Min. Max.

25 60 75 90

45 100 125 150

62 140 175 210

45 100 125 150

62 140 175 210

40 110 140 165

57 150 190 225

28 140 175 210

M74HC257

-40 to 85°C -55 to 125°C

Unit

ns4.5 7121519

ns4.5 13 20 25 30

ns4.5 18 28 35 42

ns4.5 13 20 25 30

ns4.5 18 28 35 42

ns4.5 12 22 28 33

ns4.5 17 30 38 45

ns4.5 14 28 35 42

CAPACITIVE CHARACTERISTICS

Test Condition Value

T

Symbol Parameter

C

C

C

Input Capacitance

IN

Output

OUT

Capacitance
Power Dissipation

PD

Capacitance (note

V

CC

(V)

= 25°C

A

Min. Typ. Max. Min. Max. Min. Max.

5101010pF

10 pF

47 pF

1)

1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without

load. (R ef er to Test Circ ui t). Averag e operatin g current can be obtained by t he following equation. I
Channel)

-40 to 85°C -55 to 125°C

= CPD x VCC x fIN + ICC/4 (per

CC(opr)

Unit

5/11

M74HC257

TEST CIRCUIT

TEST SWITCH

t

, t

PLH

PHL

, t

t

PZL

PLZ

t

, t

PZH

PHZ

CL = 50pF/150p F or equivalen t (includes j i g and probe capacitance )
R

= 1KΩ or equivalent

1

R

= Z

of pulse generator (typically 50Ω)

T

OUT

Open

V

CC

GND

WAVEFORM 1: PROPAGATION DELAY TIME (f=1MHz; 50% duty cycle )

6/11

M74HC257

WAVEFORM 2 :OUTPUT ENABLE AND DISABLE TIME (f=1MHz; 50% duty cycle)

7/11

M74HC257

Plastic DIP-16 (0.25) MECHANICAL DATA

mm. inch

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

8/11

P001C

SO-16 MECHANICAL DATA

M74HC257

DIM.

A 1.75 0.068
a1 0.1 0.2 0.003 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

S8° (max.)

MIN. TYP MAX. MIN. TYP. MAX.

mm. inch

PO13H

9/11

M74HC257

TSSOP16 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 1.2 0.047

A1 0.05 0.15 0.002 0.004 0.006

A2 0.8 1 1.05 0.031 0.039 0.041

b 0.19 0.30 0.007 0.012

c 0.09 0.20 0.004 0.0089

D 4.9 5 5.1 0.193 0.197 0.201

E 6.2 6.4 6.6 0.244 0.252 0.260

E1 4.3 4.4 4.48 0.169 0.173 0.176

e 0.65 BSC 0.0256 BSC

K0° 8°0° 8°

L 0.45 0.60 0.75 0.018 0.024 0.030

A2

A

A1

b

e

c

K

L

E

D

E1

PIN 1 IDENTIFICATION

10/11

1

0080338D

M74HC257

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