74HCT138DB: 3-to-8 line decoder/demultiplexer; inverting

The 74HC138; 74HCT138 decodes three binary weighted address inputs (A0, A1 and A2) to eight mutually exclusive outputs (Y0 to Y7). The device features three enable inputs (E1, E2 and E3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion to a 1-of-32 (5 to 32 lines) decoder with just four ‘138’ ICs and one inverter. The ‘138’ can be used as an eight output demultiplexer by using one of the active LOW enable inputs as the data input and the remaining enable inputs as strobes. Inputs include clamp diodes. This enables the use of current limiting resistors to interface inputs to voltages in excess of VCC.

74HCT138DB: Product Block Diagram
Outline 3d SOT338-1
Data Sheets (1)
Name/DescriptionModified Date
3-to-8 line decoder/demultiplexer; inverting (REV 6.0) PDF (195.0 kB) 74HC_HCT138 [English]28 Dec 2015
Application Notes (2)
Name/DescriptionModified Date
Live Insertion Aspects of Philips Logic Families (REV 1.0) PDF (73.0 kB) AN252 [English]13 Mar 2013
Pin FMEA 74HC/74HCT family (REV 1.0) PDF (51.0 kB) AN11044 [English]16 Mar 2011
Users Guides (1)
Name/DescriptionModified Date
HC/T User Guide (REV 1.0) PDF (508.0 kB) HCT_USER_GUIDE [English]01 Nov 1997
Selector Guides (2)
Name/DescriptionModified Date
ロジック製品セレクションガイド... (REV 1.0) PDF (38.3 MB) LOGIC_SELECTION_GUIDE_2015_JP [English]19 Nov 2015
Logic selection guide 2016 (REV 1.1) PDF (15.3 MB) 75017285 [English]08 Jan 2015
Package Information (1)
Name/DescriptionModified Date
plastic shrink small outline package; 16 leads; body width 5.3 mm (REV 1.0) PDF (306.0 kB) SOT338-1 [English]08 Feb 2016
Supporting Information (2)
Name/DescriptionModified Date
Footprint for reflow soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-REFLOW [English]08 Oct 2009
Footprint for wave soldering (REV 1.0) PDF (16.0 kB) SSOP-TSSOP-VSO-WAVE [English]08 Oct 2009
SPICE model
Ordering Information
ProductStatusFamilyVCC (V)FunctionLogic switching levelsDescriptionOutput drive capability (mA)Package versiontpd (ns)Power dissipation considerationsTamb (Cel)Rth(j-a) (K/W)Ψth(j-top) (K/W)Rth(j-c) (K/W)Package nameNo of pins
74HCT138DBActiveHC(T)4.5 - 5.5Decoders/demultiplexersTTLTTL enabled+/- 4SOT338-119low-40~12514842.0SSOP1616
Package Information
Product IDPackage DescriptionOutline VersionReflow/Wave SolderingPackingProduct StatusPart NumberOrdering code(12NC)MarkingChemical ContentRoHS / Pb Free / RHFLeadFree Conversion DateEFRIFR(FIT)MTBF(hour)MSLMSL LF
74HCT138DBSOT338-1SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE
SSOP-TSSOP-VSO-REFLOW SSOP-TSSOP-VSO-WAVE
Reel 13" Q1/T1Active74HCT138DB,118 (9351 744 20118)HCT13874HCT138DBweek 12, 200584.96.621.51E811
Bulk PackActive74HCT138DB,112 (9351 744 20112)HCT13874HCT138DBweek 12, 200584.96.621.51E811
3-to-8 line decoder/demultiplexer; inverting 74HCT138PW
Live Insertion Aspects of Philips Logic Families 74HC_T_245_Q100
Pin FMEA 74HC/74HCT family 74HC_T_597_Q100
HC/T User Guide 74HCU04PW
ロジック製品セレクションガイド... 74LVC_H_245A_Q100
Logic selection guide 2016 74LVC_H_245A_Q100
hc Spice model 74HCU04PW
plastic shrink small outline package; 16 leads; body width 5.3 mm 74HC_T_595_Q100
Footprint for reflow soldering 74HC_T_595_Q100
SSOP-TSSOP-VSO-WAVE LPC1114FDH28
74HC_T_138
HEF4094B