Fairchild Semiconductor 74LCX157SJ, 74LCX157MX, 74LCX157MTCX, 74LCX157M, 74LCX157CW Datasheet

May 1995
Revised March 1999

74LCX157 Low Voltage Quad 2-Input Multiplexer with 5V Tolerant Inputs

© 1999 Fairchild Semiconductor Corporation DS012465.prf www.fairchildsemi.com

74LCX157
Low Voltage Quad 2-Input Multiplexer with 5V Tolerant

Inputs

General Description

The LCX157 is a high-speed quad 2-input multiplexer. Four
bits of data from two sources can be selected using the
common Select and Enable inputs. The four outputs
present the selected data in the true (noninverted) form.
The LCX157 can also be used as a function generator.

The 74LCX157 is fabricated with advanced CMOS technol­ogy to achieve high speed operation while maintaining
CMOS low power dissipation.

Features

■ 5V tolerant inputs

■ 2.3V–3.6V V

CC

specifications provided

■ 5.8 ns t

PD

max (VCC = 3.3V), 10 µA ICC max

■ Power down high impedance inputs and outputs

■ ±24 mA output drive (V

CC

= 3.0V)

■ Implements patented noise/EMI reduction circuitry

■ Latch-up performance exceeds 500 mA

■ ESD performance:

Human body model > 2000V
Machine model > 200V

Ordering Code:

Devices also availab le in Tape and Reel. Specify by appending th e s uffix let t er “X” to the ordering code.

Logic Symbols

IEEE/IEC

Connection Diagram

Pin Descriptions

Order Number Package Number Package Description

74LCX157M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150” Narrow
74LCX157SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
74LCX157MTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide

Pin Names Description

I

0a–I0d

Source 0 Data Inputs

I

1a–I1d

Source 1 Data Inputs

E

Enable Input
S Select Input
Z

a–Zd

Outputs

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74LCX157

Functional Description

The LCX157 is a quad 2-input multiplexer. It selects four
bits of data from two sources un der the control of a com­mon Select input (S). The Enable input (E

) is active-LOW.

When E

is HIGH, all of the outputs (Z) are forced LOW
regardless of all other inputs. The LCX157 is the logic
implementation of a 4-pole, 2-position switch where the
position of the switch is determined by the logic levels sup­plied to the Select input. The logic equations for the outputs
are shown below:

Z

a

= E • (I1a • S + I0a • S)

Z

b

= E • (I1b • S + I0b • S)

Z

c

= E • (I1c • S + I0c • S)

Z

d

= E • (I1d • S + I0d • S)

A common use of the L CX157 is the moving of data from
two groups of registers to four common output busses. The
particular r eg is t er fr om w h ich t h e dat a c o me s i s d ete rm i n ed
by the state of the Select input. A less obvious use is as a
function generat or. The LCX157 can generate any four of

the sixteen different functions of two variables with one
variable common. This is useful for implementing gating
functions.

Tr uth Table

H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial

Logic Diagram

Please note that this diagram is provided only for the understan ding of logic operation s and should not be used t o es t im ate propagation delays.

Inputs Outputs

E

SI0I

1

Z

HX X X L

LH X L L
LH X H H
LL L X L
LLH X H

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74LCX157

Absolute Maximum Ratings(Note 1)

Recommended Operating Conditions (Note 3)

Note 1: The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated

at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the Absolute Maximum Ratings. The “Recom­mended Operating C onditions” table will def ine the conditions for ac t ual device operation.

Note 2: I

O

Absolute Maximum Rating must be observed.

Note 3: Unused inputs must be held HIGH or LOW. They may not float.

DC Electrical Characteristics

Symbol Parameter Value Conditions Units

V

CC

Supply Voltage −0.5 to +7.0 V

V

I

DC Input Voltage −0.5 to +7.0 V

V

O

DC Output Voltage −0.5 to VCC + 0.5 Output in HIGH or LOW State (Note 2) V

I

IK

DC Input Diode Current −50 VI < GND mA

I

OK

DC Output Diode Current −50 VO < GND mA

+50 V

O

> V

CC

I

O

DC Output Source/Sink Current ±50 mA

I

CC

DC Supply Current per Supply Pin ±100 mA

I

GND

DC Ground Current per Ground Pin ±100 mA

T

STG

Storage Temperature −65 to +150 °C

Symbol Parameter Min Max Units

V

CC

Supply Voltage Operating 2.0 3.6

V

Data Retention 1.5 3.6

V

I

Input Voltage 05.5V

V

O

Output Voltage HIGH or LOW State 0 V

CC

V

I

OH/IOL

Output Current VCC = 3.0V − 3.6V ±24

mAV

CC

= 2.7V − 3.0V ±12

V

CC

= 2.3V − 2.7V ±8

T

A

Free-Air Operating Temperature −40 85 °C

∆t/∆V Input Edge Rate, V

IN

= 0.8V − 2.0V, VCC = 3.0V 0 10 ns/V

Symbol Parameter Conditions

V

CC

(V)

TA = −40°C to +85°C

Units

Min Max

V

IH

HIGH Level Input Voltage 2.3 − 2.7 1.7

V

2.7 − 3.6 2.0

V

IL

LOW Level Input Voltage 2.3 − 2.7 0.7

V

2.7 − 3.6 0.8

V

OH

HIGH Level Output Voltage IOH = −100 µA2.3 − 3.6 VCC − 0.2

V

IOH = −8 mA 2.3 1.8
IOH = −12 mA 2.7 2.2
IOH = −18 mA 3.0 2.4
IOH = −24 mA 3.0 2.2

V

OL

LOW Level Output Voltage IOL = 100 µA2.3 − 3.6 0.2

V

IOH = 8 mA 2.3 0.6
IOL = 12 mA 2.7 0.4
IOL = 16 mA 3.0 0.4
IOL = 24 mA 3.0 0.55

I

I

Input Leakage Current 0 ≤ VI ≤ 5.5V 2.3 − 3.6 ±5.0 µA

I

OFF

Power-Off Leakage Current VI or VO = 5.5V 0 10 µA

I

CC

Quiescent Supply Current VI = VCC or GND 2.3 − 3.6 10

µA

3.6V ≤ VI ≤ 5.5V 2.3 − 3.6 ±10

∆I

CC

Increase in ICC per Input VIH = VCC −0.6V 2.3 − 3.6 500 µA