SN54LS138J Equivalent & Substitute Parts

Part Overview

The SN54LS138J is a 3-line to 8-line decoder/demultiplexer manufactured by Texas Instruments, classified as a logic integrated circuit. This component decodes a 3-bit binary input into one of eight mutually exclusive outputs, functioning as a 1 x 3:8 decoder/demultiplexer. The device is actively produced and maintains full RoHS3 compliance. Substitute parts are identified when equivalent functional performance can be achieved within the specified electrical and mechanical parameters of this product category.

Substiute Parts

SN54LS138J

Texas InstrumentsIn Stock: 3484SN54LS138J Datasheet

Current PartRFQ

SN74LS138N

Texas InstrumentsIn Stock: 16267SN74LS138N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN54LS138J decoder/demultiplexer is determined by the following critical parameters:

• Functional equivalence: Identical circuit configuration (1 x 3:8 decoder/demultiplexer)
• Electrical compatibility: Output current specifications and supply voltage range must support the application requirements
• Package compatibility: Through-hole mounting with 16-pin DIP package footprint
• Operating temperature range: Must encompass or overlap the required operating conditions
• Compliance status: RoHS3 compliance and active product status

The SN74LS138N qualifies as a substitute based on matching decoder/demultiplexer functionality, identical package footprint, through-hole mounting, and equivalent RoHS3 compliance. Differences in operating temperature range and output current specifications must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

Both the SN54LS138J and SN74LS138N are active products with full RoHS3 compliance from Texas Instruments. Selection between these decoder/demultiplexer parts depends on application-specific requirements:

The SN54LS138J supports extended operating temperature range (-55°C to 125°C) and lower output low current (4mA), making it suitable for industrial and military-grade applications requiring wider temperature operation.

The SN74LS138N operates within commercial temperature range (0°C to 70°C) with higher output low current capability (8mA) and narrower supply voltage tolerance (4.75V to 5.25V), positioning it for standard commercial applications.

Both parts share identical 16-pin DIP package footprint and decoder/demultiplexer functionality, enabling direct substitution when temperature and current specifications align with application constraints.

Frequently Asked Questions (FAQ)

Q: Can SN74LS138N replace SN54LS138J in all applications?

A: Substitution is valid only when the application operates within the SN74LS138N temperature range (0°C to 70°C) and output current requirements (8mA low). Applications requiring extended temperature operation (-55°C to 125°C) must use the SN54LS138J.

Q: Are the package footprints identical between these parts?

A: Both parts use 16-pin DIP packages with 0.300" (7.62mm) spacing. The SN54LS138J uses CDIP packaging while the SN74LS138N uses PDIP packaging. Both are through-hole mount and share compatible PCB footprints.

Q: What is the functional difference between these decoder/demultiplexer parts?

A: Both parts implement identical 1 x 3:8 decoder/demultiplexer logic. Functional differences do not exist; differences are limited to electrical operating ranges and temperature specifications.

Q: Do both parts meet current compliance requirements?

A: Both the SN54LS138J and SN74LS138N are RoHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards.

Q: Which part should be selected for new designs?

A: Selection is based on operating environment. Commercial applications (0°C to 70°C) can use SN74LS138N. Industrial and extended-temperature applications require SN54LS138J.