SN74F138D Equivalent & Substitute Parts

Part Overview

The SN74F138D is a Decoder/Demultiplexer logic IC manufactured by Texas Instruments, featuring a 1 x 3:8 circuit configuration in a 16-SOIC surface mount package. This component is classified as Last Time Buy, indicating discontinued production with limited availability. Identifying equivalent substitute parts is essential for ongoing design support, production continuity, and long-term component sourcing strategy.

Substiute Parts

SN74F138D

Texas InstrumentsIn Stock: 3865SN74F138D Datasheet

Current PartRFQ

SN74F138DR

Texas InstrumentsIn Stock: 11751SN74F138DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74F138D are determined by strict equivalence across the following critical parameters:

• Base Product Number: 74F138 (identical logic function and pin configuration)
• Circuit Configuration: 1 x 3:8 decoder/demultiplexer (functional equivalence)
• Package Type: 16-SOIC surface mount (mechanical and thermal compatibility)
• Electrical Specifications: Voltage supply 4.5V ~ 5.5V, output current 1mA/20mA (operational compatibility)
• Operating Temperature Range: 0°C ~ 70°C (environmental compatibility)
• Compliance Standards: ROHS3 Compliant, REACH Unaffected (regulatory equivalence)

The primary distinction between the main part and substitute is packaging format: tube versus tape & reel. This difference affects inventory management and automated assembly processes but does not alter electrical or functional characteristics.

Parameter Comparison

Engineering Selection Recommendations

The SN74F138DR is the manufacturer-recommended substitute for the SN74F138D. Both parts are manufactured by Texas Instruments and share identical electrical, functional, and mechanical specifications. The key distinction is product status: the SN74F138D is Last Time Buy with limited inventory (3796 pcs), while the SN74F138DR maintains Active status with higher availability (11672 pcs).

For new designs and production continuity, the SN74F138DR is the appropriate selection. Both parts meet ROHS3 compliance and REACH requirements, ensuring regulatory compatibility across applications. The packaging format difference (tube versus tape & reel) affects only supply chain logistics and assembly automation compatibility, not component performance or PCB integration.

Frequently Asked Questions (FAQ)

Q: Are SN74F138D and SN74F138DR electrically identical?

A: Yes. Both parts share identical electrical specifications, including voltage supply range (4.5V ~ 5.5V), output current characteristics (1mA/20mA), and operating temperature range (0°C ~ 70°C). They are functionally equivalent.

Q: What is the difference between tube and tape & reel packaging?

A: Tube packaging is used for manual handling and lower-volume applications. Tape & reel packaging is designed for automated pick-and-place assembly. The physical component and electrical performance are identical; the difference is in supply format and handling method.

Q: Can I use SN74F138DR as a direct replacement in existing designs?

A: Yes. The SN74F138DR is a direct pin-for-pin and functional replacement. No circuit modifications are required. PCB layout and schematic remain unchanged.

Q: Why is SN74F138D marked as Last Time Buy?

A: Last Time Buy status indicates Texas Instruments has discontinued production of this part number. The SN74F138DR remains in active production and is the recommended long-term alternative.

Q: Are both parts RoHS compliant?

A: Yes. Both SN74F138D and SN74F138DR are ROHS3 Compliant and REACH Unaffected, meeting current environmental and regulatory standards.

Q: Which part should I specify for new production orders?

A: Specify SN74F138DR for new designs and ongoing production. It maintains active manufacturing status and higher inventory availability while providing identical performance to the SN74F138D.