74F138SJ Decoder/Demultiplexer Equivalent & Substitute Parts

Part Overview

The 74F138SJ is a 1 x 3:8 decoder/demultiplexer logic IC manufactured by onsemi in a 16-SOP surface mount package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The 74F138 series maintains consistent functional specifications across multiple manufacturers and packaging variants, enabling direct substitution based on electrical and mechanical compatibility.

Substiute Parts

74F138SJ

onsemiIn Stock: 685274F138SJ Datasheet

Current PartRFQ

SN74F138NS

Texas InstrumentsIn Stock: 1822SN74F138NS Datasheet

DirectRFQ

SN74F138NSR

Texas InstrumentsIn Stock: 3472SN74F138NSR Datasheet

DirectRFQ

SN74F138D

Texas InstrumentsIn Stock: 3865SN74F138D Datasheet

SimilarRFQ

SN74F138DR

Texas InstrumentsIn Stock: 11751SN74F138DR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74F138SJ is determined by electrical equivalence and package compatibility. All substitute parts maintain identical circuit configuration (1 x 3:8), output current specifications (1mA/20mA), supply voltage range (4.5V ~ 5.5V), and operating temperature range (0°C ~ 70°C). The 74F138 base product number is common across all variants, confirming functional interchangeability.

Substitutes are grouped into two package categories:

Direct Package Match (16-SOP / 16-SO): SN74F138NS and SN74F138NSR from Texas Instruments provide identical 16-SOIC (0.209", 5.30mm Width) packaging, enabling pin-for-pin replacement without PCB layout modification.

Alternative Package (16-SOIC): SN74F138D and SN74F138DR from Texas Instruments use 16-SOIC (0.154", 3.90mm Width) packaging with different physical dimensions but identical electrical performance and pin configuration, requiring PCB footprint verification before substitution.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (No PCB Modification): Select SN74F138NSR (Active status, Tape & Reel packaging) or SN74F138NS (Last Time Buy status, Tube packaging). Both maintain the 16-SOIC (0.209", 5.30mm Width) package footprint identical to the 74F138SJ. SN74F138NSR is preferred for new production due to active product status and ROHS3 compliance.

For Alternative Package Selection: SN74F138DR (Active status) or SN74F138D (Last Time Buy status) provide electrical equivalence with 16-SOIC (0.154", 3.90mm Width) packaging. These parts require PCB footprint verification and layout adjustment. SN74F138DR is preferred for new production due to active product status.

Compliance Consideration: All Texas Instruments substitutes carry ROHS3 compliance and REACH Unaffected status, meeting modern regulatory requirements. The onsemi 74F138SJ RoHS status is not specified in available documentation.

Frequently Asked Questions (FAQ)

Q: Can SN74F138NS and SN74F138NSR be used interchangeably with 74F138SJ?

A: Yes. Both parts are electrically identical to the 74F138SJ and share the same 16-SOIC (0.209", 5.30mm Width) package footprint. The difference between NS and NSR variants is packaging format (Tube versus Tape & Reel), not electrical performance or physical dimensions.

Q: What is the difference between the 16-SOIC (0.209", 5.30mm) and 16-SOIC (0.154", 3.90mm) packages?

A: Both are 16-pin SOIC packages with identical pin pitch and electrical characteristics. The difference is package width: 5.30mm versus 3.90mm. This affects PCB footprint size and component placement. Parts using the narrower 3.90mm package (SN74F138D, SN74F138DR) require different PCB land patterns than the 5.30mm package (74F138SJ, SN74F138NS, SN74F138NSR).

Q: Is the 74F138SJ still available for purchase?

A: The 74F138SJ is classified as obsolete. Texas Instruments SN74F138NSR (Active status) is the recommended long-term substitute for new designs and ongoing production.

Q: Do all substitute parts meet RoHS and REACH requirements?

A: All Texas Instruments substitutes (SN74F138NS, SN74F138NSR, SN74F138D, SN74F138DR) are ROHS3 compliant and REACH Unaffected. The original 74F138SJ RoHS status is not documented.

Q: Can I use SN74F138D or SN74F138DR as a direct replacement without modifying my PCB?

A: No. While electrically equivalent, SN74F138D and SN74F138DR use a narrower 16-SOIC package (0.154", 3.90mm Width) compared to the 74F138SJ (0.209", 5.30mm Width). PCB footprint modification is required. For direct replacement without PCB changes, use SN74F138NS or SN74F138NSR.