74AHC138; 74AHCT138

3-to-8 line decoder/demultiplexer; inverting

The 74AHC138; 74AHCT138 are high-speed Si-gate CMOS devices and are pin compatible with Low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard No. 7A.

The 74AHC138; 74AHCT138 is a 3-to-8 line decoder/demultiplexer. It accepts three binary weighted address inputs (A0, A1 and A2) and, when enabled, provides eight mutually exclusive outputs (Y0 to Y7) that are LOW when selected.

There are three enable inputs: two active LOW (E1 and E2) and one active HIGH (E3). Every output will be HIGH unless E1 and E2 are LOW and E3 is HIGH.

This multiple enable function allows easy parallel expansion of the device to a 1-of-32 (5 lines to 32 lines) decoder with just four 74AHC138; 74AHCT138 devices and one inverter. The 74AHC138; 74AHCT138 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. Unused enable inputs must be permanently tied to their appropriate active HIGH or LOW state.

Features and benefits

Balanced propagation delays
All inputs have Schmitt-trigger action
Demultiplexing capability
Multiple input enable for easy expansion
Ideal for memory chip select decoding
Inputs accepts voltages higher than V_CC
For 74AHC138 only: operates with CMOS input levels
For 74AHCT138 only: operates with TTL input levels
ESD protection:
- HBM: ANSI/ESDA/JEDEC JS-001 class 2 exceeds 2000 V
- CDM: ANSI/ESDA/JEDEC JS-002 class C3 exceeds 1000 V
Multiple package options
Specified from -40 °C to +85 °C and from -40 °C to +125 °C

Parametrics

Type number	Product status	V_CC (V)	Logic switching levels	Output drive capability (mA)	t_pd (ns)	Power dissipation considerations	T_amb (°C)	R_th(j-a) (K/W)	Ψ_th(j-top) (K/W)	R_th(j-c) (K/W)	Package name
74AHC138BQ	Production	2.0 - 5.5	CMOS	± 8	4.4	low	-40~125	93	13.8	62	DHVQFN16
74AHC138D	Production	2.0 - 5.5	CMOS	± 8	4.4	low	-40~125	93	9.7	52	SO16
74AHC138PW	Production	2.0 - 5.5	CMOS	± 8	4.4	low	-40~125	125	4.6	54.7	TSSOP16
74AHCT138BQ	Production	4.5 - 5.5	TTL	± 8	4.4	low	-40~125	93	13.8	62	DHVQFN16
74AHCT138D	Production	4.5 - 5.5	TTL	± 8	4.4	low	-40~125	93	9.7	52	SO16
74AHCT138PW	Production	4.5 - 5.5	TTL	± 8	4.4	low	-40~125	125	4.6	54.7	TSSOP16

Package

Type number	Package	Package information	Reflow-/Wave soldering	Packing	Status	Marking	Orderable part number, (Ordering code (12NC))
74AHC138BQ	DHVQFN16 (SOT763-1)	SOT763-1		SOT763-1_115	Active	AHC138	74AHC138BQ,115 ( 9352 855 72115 )
74AHC138D	SO16 (SOT109-1)	SOT109-1	SO-SOJ-REFLOW SO-SOJ-WAVE	SOT109-1_118	Active	74AHC138D	74AHC138D,118 ( 9352 629 99118 )
74AHC138PW	TSSOP16 (SOT403-1)	SOT403-1	SSOP-TSSOP-VSO-WAVE	SOT403-1_118	Active	AHC138	74AHC138PW,118 ( 9352 630 00118 )
74AHCT138BQ	DHVQFN16 (SOT763-1)	SOT763-1		SOT763-1_115	Active	AHT138	74AHCT138BQ,115 ( 9352 855 73115 )
74AHCT138D	SO16 (SOT109-1)	SOT109-1	SO-SOJ-REFLOW SO-SOJ-WAVE	SOT109-1_118	Active	74AHCT138D	74AHCT138D,118 ( 9352 629 97118 )
74AHCT138PW	TSSOP16 (SOT403-1)	SOT403-1	SSOP-TSSOP-VSO-WAVE	SOT403-1_118	Active	AHCT138	74AHCT138PW,118 ( 9352 629 98118 )

Discontinuation information

Type number	Orderable part number, (Ordering code (12NC))	Last time buy date	Last time delivery date	Replacement product
74AHC138D	935262999112	2021-12-31	2022-06-30	74AHC138D
74AHC138PW	935263000112	2021-12-31	2022-06-30	74AHC138PW
74AHCT138D	935262997112	2021-12-31	2022-06-30	74AHCT138D
74AHCT138PW	935262998112	2021-12-31	2022-06-30	74AHCT138PW

Environmental information

Type number	Orderable part number	Chemical content	Leadfree conversion date
74AHC138BQ	74AHC138BQ,115	74AHC138BQ	Always Pb-free
74AHC138D	74AHC138D,118	74AHC138D	week 35, 2004
74AHC138PW	74AHC138PW,118	74AHC138PW	week 10, 2005
74AHCT138BQ	74AHCT138BQ,115	74AHCT138BQ	Always Pb-free
74AHCT138D	74AHCT138D,118	74AHCT138D	week 35, 2004
74AHCT138PW	74AHCT138PW,118	74AHCT138PW	week 10, 2005

Quality and reliability disclaimer

Documentation (10)

File name	Title	Type	Date
74AHC_AHCT138	3-to-8 line decoder/demultiplexer; inverting	Data sheet	2024-02-29
ahc138	ahc138 IBIS model	IBIS model	2013-04-07
ahct138	ahct138 IBIS model	IBIS model	2013-04-07
SOT763-1	plastic, leadless dual in-line compatible thermal enhanced very thin quad flat package; 16 terminals; 0.5 mm pitch; 3.5 mm x 2.5 mm x 1 mm body	Package information	2023-05-11
SO-SOJ-WAVE	Footprint for wave soldering	Wave soldering	2009-10-08
SO-SOJ-REFLOW	Footprint for reflow soldering	Reflow soldering	2009-10-08
WAVE_BG-BD-1	Wave soldering profile	Wave soldering	2021-09-08
SOT109-1	plastic, small outline package; 16 leads; 1.27 mm pitch; 9.9 mm x 3.9 mm x 1.75 mm body	Package information	2023-11-07
SOT403-1	plastic, thin shrink small outline package; 16 leads; 5 mm x 4.4 mm x 1.2 mm body	Package information	2023-11-08
SSOP-TSSOP-VSO-WAVE	Footprint for wave soldering	Wave soldering	2009-10-08

Support

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Models

File name	Title	Type	Date
ahc138	ahc138 IBIS model	IBIS model	2013-04-07
ahct138	ahct138 IBIS model	IBIS model	2013-04-07

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