74LCX138MTCX - National Semiconductor

TL/F/12417

74LCX138 Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs

November 1996

74LCX138

Low Voltage 1-of-8 Decoder/Demultiplexer

with 5V Tolerant Inputs

General Description

The LCX138 is a high-speed 1-of-8 decoder/demultiplexer.

This device is ideally suited for high-speed bipolar memory

chip select address decoding. The multiple input enables

allow parallel expansion to a 1-of-24 decoder using just

three LCX138 devices or a 1-of-32 decoder using four

LCX138 devices and one inverter.

The 74LCX138 is fabricated with advanced CMOS technol-

ogy to achieve high speed operation while maintaining

CMOS low power dissipation.

Features

Y5V tolerant inputs

Y6.0 ns tPD max, 10 mAI

CCQ max

YPower down high impedance inputs and outputs

YSupports live insertion/withdrawal

Y2.0V–3.6V VCC supply operation

Yg24 mA output drive

YImplements patented Quiet SeriesTM noise/EMI reduc-

tion circuitry

YFunctionally compatible with 74 series 138

YLatch-up performance exceeds 500 mA

YESD performance:

Human body model l2000V

Machine model l200V

Logic Symbols

TL/F/12417–1

IEEE/IEC

TL/F/12417– 2

Connection Diagram

Pin Assignment

for SOIC and TSSOP

TL/F/12417– 3

Pin Names Description

A0–A2Address Inputs

E1–E2Enable Inputs

E3Enable Input

O0–O7Outputs

SOIC JEDEC SOIC EIAJ TSSOP

Order Number 74LCX138M 74LCX138SJ 74LCX138MTC

74LCX138MX 74LCX138SJX 74LCX138MTCX

See NS Package Number M16A M16D MTC16

Quiet SeriesTM is a trademark of National Semiconductor Corporation.

C1996 National Semiconductor Corporation RRD-B30M17/Printed in U. S. A. http://www.national.com

Functional Description

The LCX138 high-speed 1-of-8 decoder/demultiplexer ac-

cepts three binary weighted inputs (A0,A

) and, when

enabled, provides eight mutually exclusive active-LOW out-

puts (O0–O7). The LCX138 features three Enable inputs,

two active-LOW (E1,E

) and one active-HIGH (E3). All out-

puts will be HIGH unless E1and E2are LOW and E3is

HIGH.

The LCX138 can be used as an 8-output demultiplexer by

using one of the active LOW Enable inputs as the data input

and the other Enable inputs as strobes. The Enable inputs

which are not used must be permanently tied to their appro-

priate active-HIGH or active-LOW state.

Truth Table

Inputs Outputs

E1E2E3A0A1A2O0O1O2O3O4O5O6O7

HXXXXXHHHHHHHH

XHXXXXHHHHHHHH

XXLXXXHHHHHHHH

LLHL LL LHHHHHHH

LLHHLLHLHHHHHH

LLHLHLHHLHHHHH

LLHHHLHHHLHHHH

LLHLLHHHHHLHHH

LLHHLHHHHHHLHH

LLHLHHHHHHHHLH

LLHHHHHHHHHHHL

HIGH Voltage Level

LeLOW Voltage Level

XeImmaterial

Logic Diagram

TL/F/12417– 4

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Symbol Parameter Value Conditions Units

VCC Supply Voltage b0.5 to a7.0 V

VIDC Input Voltage b0.5 to a7.0 V

VODC Output Voltage b0.5 to VCC a0.5 Output in High or Low State (Note 2) V

IIK DC Input Diode Current b50 VIkGND mA

IOK DC Output Diode Current b50 VOkGND mA

a50 VOlVCC

IODC Output Source/Sink Current g50 mA

ICC DC Supply Current per Supply Pin g100 mA

IGND DC Ground Current per Ground Pin g100 mA

TSTG Storage Temperature b65 to a150 §C

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’’ table are not guaranteed at the Absolute Maximum Ratings. The ‘‘Recommended Operating

Conditions’’ table will define the conditions for actual device operation.

Note 2: IOAbsolute Maximum Rating must be observed.

Recommended Operating Conditions

Symbol Parameter Min Max Units

VCC Supply Voltage Operating 2.0 3.6 V

Data Retention 1.5 3.6

VIInput Voltage 0 5.5 V

VOOutput Voltage HIGH or LOW State 0 VCC V

IOH/IOL Output Current VCC e3.0V– 3.6V g24 mA

VCC e2.7V g12

TAFree-Air Operating Temperature b40 85 §C

Dt/DV Input Edge Rate, VIN e0.8V– 2.0V, VCC e3.0V 0 10 ns/V

DC Electrical Characteristics

Symbol Parameter Conditions VCC TAeb

40§Ctoa

85§CUnits

(V) Min Max

VIH HIGH Level Input Voltage 2.7–3.6 2.0 V

VIL LOW Level Input Voltage 2.7–3.6 0.8 V

VOH HIGH Level Output Voltage IOH eb

100 mA 2.7–3.6 VCC b0.2 V

IOH eb

12 mA 2.7 2.2 V

IOH eb

18 mA 3.0 2.4 V

IOH eb

24 mA 3.0 2.2 V

VOL LOW Level Output Voltage IOL e100 mA 2.7–3.6 0.2 V

IOL e12 mA 2.7 0.4 V

IOL e16 mA 3.0 0.4 V

IOL e24 mA 3.0 0.55 V

IIInput Leakage Current 0 sVIs5.5V 2.7–3.6 g5.0 mA

IOFF Power-Off Leakage Current VIor VOe5.5V 0 10 mA

ICC Quiescent Supply Current VIeVCC or GND 2.7–3.6 10 mA

3.6V sVI,V

Os5.5V 2.7–3.6 g10 mA

DICC Increase in ICC per Input VIH eVCC b0.6V 2.7–3.6 500 mA

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AC Electrical Characteristics (Preliminary)

Symbol Parameter

TAeb

40§Ctoa

85§C

Units

VCC e3.3V g0.3V VCC e2.7V

Min Max Min Max

tPHL Propagation Delay 1.5 6.0 1.5 7.0 ns

tPLH Anto Yn1.5 6.0 1.5 7.0

tPHL Propagation Delay 1.5 6.5 1.5 7.5 ns

tPLH E3to Yn1.5 6.5 1.5 7.5

tPHL Propagation Delay 1.5 6.0 1.5 7.0 ns

tPLH E1or E2to Yn1.5 6.0 1.5 7.0

tOSHL Output to Output Skew (Note 3) 1.0 ns

tOSLH 1.0

Note 3: Skew is defined as the absolute value of the difference between the actual propagation delay for any two separate outputs of the same device. The

specification applies to any outputs switching in the same direction, either HIGH to LOW (tOSHL) or LOW to HIGH (tOSLH).

Dynamic Switching Characteristics

Symbol Parameter Conditions VCC

(V)

TAe25§CUnits

Typical

VOLP Quiet Output Dynamic Peak VOL CLe50 pF, VIH e3.3V, VIL e0V 3.3 0.8 V

VOLV Quiet Output Dynamic Valley VOL CLe50 pF, VIH e3.3V, VIL e0V 3.3 b0.8 V

Capacitance

Symbol Parameter Conditions Typical Units

CIN Input Capacitance VCC eOpen, VIe0V or VCC 7pF

OUT Output Capacitance VCC e3.3V, VIe0V or VCC 8pF

PD Power Dissipation Capacitance VCC e3.3V, VIe0V or VCC,Fe10 MHz 25 pF

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74LCX138 Ordering Information

The device number is used to form part of a simplified purchasing code where the package type and temperature range are

defined as follows:

TL/F/12417– 5

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Physical Dimensions inches (millimeters) unless otherwise noted

16-Lead (0.0150×Wide) Molded Small Outline Package, JEDEC

Order Number 74LCX138M or 74LCX138MX

NS Package Number M16A

16-Lead Small Outline Package EIAJ (SJ)

Order Number 74LCX138SJ or 74LCX138SJX

NS Package Number M16D

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74LCX138 Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs

Physical Dimensions All dimensions are in millimeters (Continued)

16-Lead Thin Shrink Small Outline Package (MTC)

Order Number 74LCX138MTC or 74LCX138MTCX

NS Package Number MTC16

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failure to perform, when properly used in accordance support device or system, or to affect its safety or

with instructions for use provided in the labeling, can effectiveness.

be reasonably expected to result in a significant injury

to the user.

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National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.