SN74LS139AD Equivalent & Substitute Parts

Part Overview

The SN74LS139AD is a Decoder/Demultiplexer logic integrated circuit manufactured by Texas Instruments, featuring a 1 x 2:4 circuit configuration in a 16-SOIC surface mount package. This component is classified as discontinued at DiGi Electronics, making identification of functional equivalents essential for ongoing design support and component procurement.

The SN74LS139AD operates as a single-supply logic device with a voltage range of 4.75V to 5.25V and supports operating temperatures from 0°C to 70°C. With 1,350 pieces currently in stock, alternative part numbers provide continued access to equivalent decoder/demultiplexer functionality for applications requiring this logic family.

Substiute Parts

SN74LS139AD

Texas InstrumentsIn Stock: 1441SN74LS139AD Datasheet

Current PartRFQ

SN74LS139ADR

Texas InstrumentsIn Stock: 25097SN74LS139ADR Datasheet

DirectRFQ

SN74LS155AD

Texas InstrumentsIn Stock: 1120SN74LS155AD Datasheet

Parametric EquivalentRFQ

SN74S139AD

Texas InstrumentsIn Stock: 1207SN74S139AD Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS139AD are qualified based on the following critical parameters that determine functional interchangeability:

• Circuit Type & Configuration: All substitutes maintain the Decoder/Demultiplexer 1 x 2:4 topology with 2 independent circuits
• Package & Mounting: All substitutes use 16-SOIC surface mount packaging with identical 0.154" (3.90mm) width
• Electrical Specifications: All substitutes maintain identical voltage supply range (4.75V ~ 5.25V), output current ratings (400µA high, 8mA low), and operating temperature range (0°C ~ 70°C)
• Compliance & Certifications: All substitutes maintain ROHS3 compliance, MSL Level 1, and identical ECCN/HTSUS classifications

The substitute parts are differentiated by series designation (74LS vs. 74S), packaging format (Tube vs. Cut Tape/Digi-Reel), and product lifecycle status.

Parameter Comparison

Engineering Selection Recommendations

SN74LS139ADR is the primary substitute for the SN74LS139AD. Both parts share identical electrical specifications, circuit configuration, and package geometry. The SN74LS139ADR maintains Active product status with significantly higher inventory availability (24,998 pieces) and is supplied in Cut Tape and Digi-Reel packaging formats, providing flexibility for both prototype and production-volume procurement.

SN74LS155AD is a parametric equivalent offering identical electrical performance and package specifications. This part carries Last Time Buy status, indicating limited future availability. Selection of this substitute should account for long-term supply chain considerations.

SN74S139AD is a parametric equivalent from the 74S logic series, maintaining all critical electrical and mechanical parameters. This part holds Active product status with stable inventory levels. The 74S series designation indicates potential differences in propagation delay and power consumption characteristics not specified in the provided parameters; however, functional substitution is supported within the defined parameter set.

Frequently Asked Questions (FAQ)

Q: Can SN74LS139ADR be used as a direct replacement for SN74LS139AD?

A: Yes. Both parts are identical in circuit configuration (1 x 2:4 Decoder/Demultiplexer), electrical specifications (4.75V ~ 5.25V supply, 400µA/8mA output current), package type (16-SOIC), and mounting method (surface mount). The difference is packaging format: SN74LS139AD is supplied in Tube, while SN74LS139ADR is supplied in Cut Tape and Digi-Reel. Electrical and mechanical compatibility is complete.

Q: What is the difference between SN74LS139AD and SN74LS155AD?

A: Both parts are functionally equivalent with identical circuit configuration, electrical specifications, and package geometry. The primary difference is the base product number designation (74LS139 vs. 74LS155). SN74LS155AD carries Last Time Buy status, indicating reduced future availability compared to the active SN74LS139ADR.

Q: Can SN74S139AD replace SN74LS139AD?

A: SN74S139AD maintains all specified electrical parameters (voltage supply, output current, operating temperature) and identical package specifications (16-SOIC surface mount). Both are Decoder/Demultiplexer 1 x 2:4 circuits with 2 independent circuits. The 74S series designation indicates a different logic family; however, within the provided parameter specifications, functional substitution is supported.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All substitute parts listed (SN74LS139ADR, SN74LS155AD, SN74S139AD) maintain ROHS3 compliance, Moisture Sensitivity Level 1, and identical ECCN/HTSUS classifications as the original SN74LS139AD.

Q: Which substitute has the best availability?

A: SN74LS139ADR has the highest inventory availability at 24,998 pieces and maintains Active product status, making it the most suitable choice for ongoing procurement requirements.