ST M74HCT157 User Manual

M74HCT157

QUAD 2 CHANNEL MULTIPLEXER

■ HIGH SPEED:

t

= 16ns (TYP.) at VCC = 4.5V

PD

■ LOW POWER DISSIPATION:

I

= 4µA(MAX.) at TA=25°C

CC

■ COMPA TIBLE WITH TTL OUTPUTS :

V

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

IH

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

| = IOL = 4mA (MIN)

OH

■ BALANCED PROPAGATION DELAYS:

t

≅ t

PHL

PLH

■ PIN AND FUNCTION COMPATIBLE WITH

74 SERIES 157

DESCRIPTION

The M74HCT157 is an high s peed CM OS QUA D
2 CHANNEL MULTIPLEXER fabricated with
silicon gate C

2

MOS technology.
This device consists of four 2-input digital
multiplexer with common select and strobe inputs.
When the STROBE

(ST) input is held high,
selection of data is inhibited and all the outputs
become low. The SELECT decodi ng determines

TSSOPDIP SOP

ORDER CODES

PACKAGE TUBE T & R

DIP M74HCT157B1R

SOP M74HCT157M1R M74HCT157RM13TR

TSSOP M74HCT157TTR

whether the A or B inputs get routed to their
corresponding Y outputs.
All inputs are equipped with protection circuits
against static discharge and transient excess
voltage.

PIN CONNECTION AND IEC LOGIC SYMBOLS

1/9September 2001

M74HCT157

INPUT AND OUTPUT EQUIVALENT CIRCUIT PIN DESCRIPTION

PIN No SYMBOL NAME AND FUNCTION

1 SELECT Common Data Select

2, 5, 11, 14 1A to 4A Data Inputs From

3, 6, 10, 13 1B to 4B Data Inputs From

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

15 STROBE

8 GND Ground (0V)

16 V

TRUTH TABLE

INPUTS OUTPUTS

CC

Input

Source A

Source B

Strobe Inputs

Positive Supply Voltage

STROBE

HXXXL

LLLXL
LLHXH
LHXLL
LHXHH

X : Don’t Care

LOGIC DIAGRAM

SELECT A B Y

2/9

M74HCT157

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

, t

Input Rise and Fall Time (VCC = 4.5 to 5.5V)

f

-0.5 to +7 V

± 20 mA
± 20 mA
± 25 mA
± 50 mA

500(*) mW

-65 to +150 °C

300 °C

4.5 to 5.5 V

CC
CC

-55 to 125 °C
0 to 500 ns

V
V

V
V

3/9