SN74ALS137AD Equivalent & Substitute Parts

Part Overview

The SN74ALS137AD is a 1 x 3:8 line decoder/demultiplexer manufactured by Texas Instruments in the 74ALS logic series. This component features a 16-SOIC surface mount package and operates with a single 4.5V to 5.5V supply voltage across a 0°C to 70°C temperature range. The part is classified as Last Time Buy, indicating limited future availability. Identifying equivalent and substitute parts is essential for design continuity, long-term sourcing strategy, and production planning when original inventory becomes constrained.

Substiute Parts

SN74ALS137AD

Texas InstrumentsIn Stock: 783SN74ALS137AD Datasheet

Current PartRFQ

SN74HCS137DR

Texas InstrumentsIn Stock: 2785SN74HCS137DR Datasheet

MFR RecommendedRFQ

SN74ALS138AD

Texas InstrumentsIn Stock: 2021SN74ALS138AD Datasheet

Parametric EquivalentRFQ

SN74AS138D

Texas InstrumentsIn Stock: 1175SN74AS138D Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74ALS137AD are classified based on strict electrical and mechanical compatibility criteria:

Parametric Equivalents maintain identical or compatible electrical specifications within the allowed operating parameters:

• Voltage supply range compatibility (4.5V ~ 5.5V)
• Output current specifications (400µA, 8mA)
• Operating temperature range (0°C ~ 70°C)
• Identical circuit configuration (1 x 3:8)
• Identical package type (16-SOIC)

Manufacturer Recommended Substitute offers functional equivalence with extended operating parameters:

• Broader voltage supply range (2V ~ 6V)
• Extended operating temperature range (-40°C ~ 125°C)
• Compatible circuit configuration (1 x 3:8)
• Identical package type (16-SOIC)
• Different output current specifications (7.8mA, 7.8mA)

All substitutes maintain the same package footprint, pinout compatibility, and functional decoder/demultiplexer operation.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications): SN74ALS138AD and SN74AS138D are parametric equivalents suitable for direct substitution. Both maintain the 4.5V to 5.5V supply voltage range, 0°C to 70°C operating temperature, and identical output current characteristics. SN74AS138D carries Active product status, providing superior long-term availability compared to the Last Time Buy designation of the original part.

For Extended Operating Conditions: SN74HCS137DR is the manufacturer-recommended substitute, offering extended voltage supply range (2V to 6V) and expanded operating temperature range (-40°C to 125°C). This part is classified as Active and provides greater design flexibility for applications requiring broader environmental specifications. Output current specifications differ (7.8mA symmetric vs. 400µA/8mA asymmetric), requiring verification of load compatibility in the target application.

Compliance and Certification: All substitute parts maintain ROHS3 compliance, REACH unaffected status, and identical EAR99 export classification, ensuring regulatory continuity across substitution options.

Frequently Asked Questions (FAQ)

Q: Can SN74ALS138AD replace SN74ALS137AD directly? A: Yes. Both parts share identical electrical specifications: 4.5V to 5.5V supply voltage, 0°C to 70°C operating temperature, 1 x 3:8 circuit configuration, 16-SOIC package, and 400µA/8mA output current ratings. The primary difference is base product number (138 vs. 137), but functional operation and pinout are compatible.

Q: What is the difference between SN74AS138D and SN74ALS137AD? A: Both parts maintain identical electrical parameters and package specifications. The distinction lies in logic series: 74AS (Advanced Schottky) versus 74ALS (Advanced Low-power Schottky). SN74AS138D carries Active product status, ensuring continued availability, while SN74ALS137AD is Last Time Buy.

Q: When should SN74HCS137DR be selected over parametric equivalents? A: SN74HCS137DR is appropriate when applications require extended voltage supply range (2V to 6V) or expanded operating temperature range (-40°C to 125°C). The 74HCS series (High-speed CMOS) differs from 74ALS/74AS (TTL-based logic), resulting in different output current characteristics (7.8mA symmetric). Verify load requirements before substitution.

Q: Are all substitute parts available in the same package? A: Yes. All listed substitutes use the 16-SOIC (0.154", 3.90mm Width) surface mount package, ensuring identical PCB footprint and reflow soldering compatibility.

Q: Do substitute parts maintain the same compliance certifications? A: Yes. All substitute parts are ROHS3 compliant, REACH unaffected, and classified as EAR99 for export purposes, matching the original part's regulatory status.