74F138SC Equivalent & Substitute Parts

Part Overview

The 74F138SC is a decoder/demultiplexer integrated circuit manufactured by onsemi, featuring a 1 x 3:8 configuration in a 16-SOIC package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new designs. The 74F138 series decoder/demultiplexer is widely used in digital logic applications requiring address decoding and signal routing functions.

Substiute Parts

74F138SC

onsemiIn Stock: 146174F138SC Datasheet

Current PartRFQ

SN74F138DR

Texas InstrumentsIn Stock: 11751SN74F138DR Datasheet

DirectRFQ

SN74F138NSR

Texas InstrumentsIn Stock: 3472SN74F138NSR Datasheet

SimilarRFQ

SN74F138D

Texas InstrumentsIn Stock: 3865SN74F138D Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74F138SC are classified based on compatibility with the following critical parameters:

Electrical Parameters (Must Match):

• Circuit configuration: 1 x 3:8 decoder/demultiplexer
• Voltage supply range: 4.5V ~ 5.5V
• Output current specifications: 1mA (high), 20mA (low)
• Operating temperature range: 0°C ~ 70°C

Mechanical Parameters (Allowable Variations):

• Package type: 16-SOIC or 16-SO (both surface mount)
• Package width tolerance: 0.154" (3.90mm) or 0.209" (5.30mm)
• Mounting type: Surface mount

Substitution Categories:

Direct Manufacturer Equivalent (SN74F138DR): Identical electrical specifications, same package footprint (16-SOIC 0.154"), active product status, supplied in Tape & Reel packaging.

Similar Manufacturer Equivalent (SN74F138NSR): Identical electrical specifications, compatible 16-SO package (0.209" width), active product status, supplied in Tape & Reel packaging. Package width variation requires PCB layout verification.

Parametric Equivalent (SN74F138D): Identical electrical specifications, same package footprint (16-SOIC 0.154"), Last Time Buy product status, supplied in Tube packaging.

Parameter Comparison

Engineering Selection Recommendations

For New Designs and Immediate Availability: SN74F138DR (Texas Instruments) is the primary substitute. This part maintains identical electrical and mechanical specifications to the 74F138SC, features active product status ensuring long-term availability, and carries ROHS3 compliance certification. Tape & Reel packaging supports automated assembly processes.

For Pin-Compatible Footprint Matching: SN74F138D (Texas Instruments) provides identical package footprint (16-SOIC 0.154") and electrical parameters. However, this part carries Last Time Buy status, indicating limited future availability. Selection should account for long-term supply chain requirements.

For Package Width Tolerance Applications: SN74F138NSR (Texas Instruments) is suitable when PCB layout permits the wider 16-SO package (0.209" width). This part maintains active product status and ROHS3 compliance. Package width variation requires verification against PCB design constraints before implementation.

Frequently Asked Questions (FAQ)

Q: Can SN74F138NSR be used as a direct replacement for 74F138SC? A: SN74F138NSR is electrically equivalent but features a wider package (0.209" vs. 0.154"). Direct PCB substitution is not possible without layout modification. Verify PCB spacing and trace routing before implementation.

Q: What is the difference between Tape & Reel and Tube packaging? A: Tape & Reel packaging (SN74F138DR, SN74F138NSR) is optimized for automated pick-and-place assembly. Tube packaging (SN74F138D) is suitable for manual assembly or lower-volume applications. Packaging selection depends on manufacturing process requirements.

Q: Why is 74F138SC listed as obsolete? A: Obsolete status indicates the manufacturer (onsemi) has discontinued production. Texas Instruments SN74F138 variants remain in active production, providing continued availability for this decoder/demultiplexer function.

Q: Are all substitute parts ROHS3 compliant? A: Yes. SN74F138DR, SN74F138NSR, and SN74F138D all carry ROHS3 compliance certification. The original 74F138SC RoHS status was not specified in available documentation.

Q: What is the MSL (Moisture Sensitivity Level) for these parts? A: All parts in this family carry MSL 1 (Unlimited), indicating no moisture sensitivity precautions are required during storage or handling.

Q: Can these parts be used interchangeably in existing 74F138SC designs? A: SN74F138DR and SN74F138D are pin-compatible and footprint-compatible with 74F138SC. SN74F138NSR requires PCB layout verification due to package width variation. All three maintain identical electrical specifications and operating parameters.