Datasheet M74HC238 Datasheet (ST)

M74HC238

3 TO 8 LINE DECODER

■ HIGH SPEED:

t

= 15ns (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 = 4mA (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 238

DESCRIPTION

The M74HC238 is an hi gh speed CMOS 3 TO 8
LINE DECODER fabricated with silicon gate

2

C

MOS technology.
If the device is enabled, 3 binary select inputs (A,
B and C) determine which one of outputs will go
high. When enable input G1 is held "Low" or either
G2A

or G2B is held "High" decoding func tion is

TSSOPDIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP M74HC238B1R

SOP M74HC238M1R M74HC238RM13TR

TSSOP M74HC238TTR

inhibited and all the 8 outputs go low. Three
enable inputs are provided to ease cascade
connection and application of this address
decoder in memory systems.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

1/10July 2001

M74HC238

INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

1, 2, 3 A, B, C Data Inputs

4, 5 G2A

6 G1 Data Enable Input (Active

15, 14, 13,

12, 1 1, 10, 9,

7
8 GND Ground (0V)

16 V

TRUTH TABLE

G2B Enable Input (Active

Y0 to Y7 Outputs

CC

LOW)

HIGH)

Positive Supply Voltage

INPUTS

ENABLE SELECT

G2B

G2A G1 C B A Y0Y1Y2Y3Y4Y5Y6Y7

XXLXXXLLLLLLLL NONE
XHXXXXLLLLLLLL NONE
HXXXXXLLLLLLLL NONE
LLHLLLHLLLLLLL Y0
LLHLLHLHLLLLLL Y1
LLHLHLLLHLLLLL Y2
LLHLHHLLLHLLLL Y3
LLHHLLLLLLHLLL Y4
LLHHLHLLLLLHLL Y5
LLHHHLLLLLLLHL Y6
LLHHHHLLLLLLLH Y7

X : Don’t Care

OUTPUTS

SELECTED

OUTPUT

LOGIC DIAGRAM

This log i c diagram has not be used to est i m at e propagation delays

2/10

M74HC238

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
± 25 mA
± 50 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

3/10

M74HC238

DC SPECIFICATIONS

Symbol Parameter

V

V

V

V

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
Quiescent Supply

CC

Current

Test Conditions 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

IO=-20 µA
I

=-20 µA

O

I

=-20 µA

O

I

=-4.0 mA

O

I

=-5.2 mA

O

IO=20 µA
I

=20 µA

O

I

=20 µA

O

I

=4.0 mA

O

I

=5.2 mA

O

= VCC or GND

V

I

= 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

44080µA

Unit

V4.5 3.15 3.15 3.15

V4.5 1.35 1.35 1.35

V

V

AC ELECTRICAL CHARACTERISTICS (C

Test Conditions Value

Symbol Parameter

t

TLH tTHL

t

PLH tPHL

t

PLH tPHL

t

PLH tPHL

Output Transition
Time

Propagation Delay
Time (A, B, C - Y)

Propagation Delay
Time (G1 - Y)

Propagation Delay
Time (G2

- Y)

V

CC

(V)

2.0 30 75 95 110

6.0 7131619

2.0 50 150 190 225

6.0 15 26 32 38

2.0 50 150 190 225

6.0 15 26 32 38

2.0 50 150 190 225

6.0 15 26 32 38

= 50 pF, Input tr = tf = 6ns)

L

T

= 25°C

A

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

-40 to 85°C -55 to 125°C

Unit

ns4.5 8151922

ns4.5 17 30 38 45

ns4.5 17 30 38 45

ns4.5 17 30 38 45

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M74HC238

CAPACITIVE CHARACTERISTICS

Test Conditions Value

T

Symbol Parameter

V

CC

(V)

C

C

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 Circui t). Averag e operating current can be obtained by the following equation. I

Input Capacitance

IN

Power Dissipation

PD

Capacitance (note 1)5.0 53 pF

5.0 5101010pF

= 25°C

A

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

TEST CIRCUIT

-40 to 85°C -55 to 125°C

= CPD x VCC x fIN + ICC

CC(opr)

Unit

CL = 50pF or equivalent (includes jig and p robe capacit ance)
R

= Z

of pulse generator (typically 50Ω)

T

OUT

5/10

M74HC238

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

6/10

M74HC238

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

P001C

7/10

M74HC238

SO-16 MECHANICAL DATA

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. M AX.

mm. inch

8/10

PO13H

M74HC238

TSSOP16 MECHANICAL DATA

mm. inch

DIM.

MIN. TYP MAX. MIN. TYP. M AX.

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

1

0080338D

9/10

M74HC238

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