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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.

This product has been discontinued, click here for discontinuation information and replacement parts.

Features and benefits

  • Wide supply voltage range from 2.0 to 6.0 V

  • CMOS low power dissipation

  • High noise immunity

  • Latch-up performance exceeds 100 mA per JESD 78 Class II Level B

  • Demultiplexing capability

  • Multiple input enable for easy expansion

  • Ideal for memory chip select decoding

  • Active LOW mutually exclusive outputs

  • Input levels:

    • For 74HC138: CMOS level

    • For 74HCT138: TTL level

  • Complies with JEDEC standards:

    • JESD8C (2.7 V to 3.6 V)

    • JESD7A (2.0 V to 6.0 V)

  • 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 Package name
74HCT138DB End of life SSOP16

PCB Symbol, Footprint and 3D Model

Model Name Description

Package

All type numbers in the table below are discontinued. See the table Discontinuation information for more information.

Type number Orderable part number, (Ordering code (12NC)) Status Marking Package Package information Reflow-/Wave soldering Packing
74HCT138DB 74HCT138DB,112
(935174420112)
Obsolete no package information
74HCT138DB,118
(935174420118)
Obsolete

Environmental information

All type numbers in the table below are discontinued. See the table Discontinuation information for more information.

Type number Orderable part number Chemical content RoHS RHF-indicator
74HCT138DB 74HCT138DB,112 74HCT138DB rohs rhf rhf
74HCT138DB 74HCT138DB,118 74HCT138DB rohs rhf rhf
Quality and reliability disclaimer

Documentation (4)

File name Title Type Date
74HC_HCT138 3-to-8 line decoder/demultiplexer; inverting Data sheet 2024-02-26
AN11044 Pin FMEA 74HC/74HCT family Application note 2019-01-09
hc HC/HCT Spice model SPICE model 2022-02-17
HCT_USER_GUIDE HC/T User Guide User manual 1997-10-31

Support

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Models

File name Title Type Date
hc HC/HCT Spice model SPICE model 2022-02-17

PCB Symbol, Footprint and 3D Model

Model Name Description

How does it work?

The interactive datasheets are based on the Nexperia MOSFET precision electrothermal models. With our interactive datasheets you can simply specify your own conditions interactively. Start by changing the values of the conditions. You can do this by using the sliders in the condition fields. By dragging the sliders you will see how the MOSFET will perform at the new conditions set.