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Diodes 74HC138 User Manual

Description, Features, Pin assignments

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74HC138

Document number: DS35488 Rev.3 - 2

1 of 10

www.diodes.com

June 2013

© Diodes Incorporated

74HC138

3 TO 8 LINE DECODER DEMULTIPLEXER

Description

The 74HC138 is a high speed CMOS device.

The device accepts a three bit binary weighted address on input pins

A0, A1 and A2 and when enabled will produce one active low output

with the remaing seven being high.

There are two active LOW enable inputs E1 and E2, and one active

HIGH enable input E3. The disabled device state results in all outputs

being high. The enable state occurs with E1 and E2 asserted low and

E3 asserted high.

The multiple enable lines allow for the parallel expansion of decoders

to create 4-to-16 line versions with no additional parts and 5-to-32

versions with the addition of a single inverter.

Features

Wide Supply Voltage Range from 2.0V to 6.0V

Sinks or sources 8 mA at V

CC

= 4.5V

CMOS low power consumption

Schmitt Trigger Action at All Inputs

Inputs Accept up to 6.0V

ESD Protection Tested per JESD 22

Exceeds 200-V Machine Model (A115-A)

Exceeds 2000-V Human Body Model (A114-A)

Exceeds 1000-V Charged Device Model (C101C)

Latch-Up Exceeds 100mA per JESD 78D, Class II

Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)

Halogen and Antimony Free. “Green” Device (Note 3)

Pin Assignments

Applications

Memory chip select decoding

 Demultiplexing

Single line peripheral control

Allow simple serial bit streams from a microcontroller to control as

many peripheral lines as needed



Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.

2. See http://www.diodes.com for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and Lead-free.

3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.

Click here for ordering information, located at the end of datasheet