SN74LS156D Equivalent & Substitute Parts

Part Overview

The SN74LS156D is a Decoder/Demultiplexer logic integrated circuit manufactured by Texas Instruments, featuring a 2 x 1:4 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 necessary to ensure project continuity and secure long-term component supply for applications requiring this decoder/demultiplexer functionality.

Substiute Parts

SN74LS156D

Texas InstrumentsIn Stock: 726SN74LS156D Datasheet

Current PartRFQ

SN74LS156DR

Texas InstrumentsIn Stock: 4097SN74LS156DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS156D are determined by strict equivalence across the following critical parameters:

• Decoder/Demultiplexer type with identical 2 x 1:4 circuit configuration
• 16-SOIC surface mount package with 0.154" (3.90mm) width specification
• Single supply voltage range of 4.75V ~ 5.25V
• Output current specifications: 100µA (high), 8mA (low)
• Operating temperature range: 0°C ~ 70°C
• Compliance certifications: ROHS3, MSL Level 1

The SN74LS156DR qualifies as a direct substitute based on identical electrical specifications, package dimensions, and functional characteristics. The primary distinction is packaging format: the SN74LS156D is supplied in Tube packaging, while the SN74LS156DR is supplied in Tape & Reel (TR) format.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS156DR is the direct substitute for the SN74LS156D. Both components are manufactured by Texas Instruments with identical electrical and mechanical specifications. The SN74LS156DR maintains Active product status, ensuring continued availability and supply chain reliability compared to the Last Time Buy status of the SN74LS156D.

Both parts satisfy ROHS3 compliance and MSL Level 1 requirements. The functional equivalence is complete across all specified parameters. Selection between these parts should be based on packaging requirements: Tube format for the SN74LS156D or Tape & Reel format for the SN74LS156DR.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS156DR be used as a direct replacement for the SN74LS156D?

A: Yes. The SN74LS156DR is electrically and mechanically equivalent to the SN74LS156D. Both components feature identical 2 x 1:4 decoder/demultiplexer circuits, 16-SOIC packages, voltage specifications (4.75V ~ 5.25V), and output current ratings (100µA, 8mA). The only difference is packaging format: Tube versus Tape & Reel.

Q: What is the significance of the Last Time Buy status for the SN74LS156D?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part. Existing inventory may be limited. The SN74LS156DR, with Active status, represents the recommended alternative for new designs and long-term supply assurance.

Q: Are there any compatibility concerns when switching from SN74LS156D to SN74LS156DR?

A: No compatibility concerns exist. Both parts are pin-compatible, functionally identical, and meet the same compliance standards (ROHS3, MSL Level 1). The 16-SOIC package dimensions are identical (0.154", 3.90mm width), ensuring PCB footprint compatibility.

Q: What does the packaging format difference (Tube vs. Tape & Reel) mean for component selection?

A: Tube packaging is suitable for manual handling and smaller quantity orders. Tape & Reel packaging is optimized for automated assembly processes and larger production volumes. The choice depends on manufacturing process requirements and order quantities, not on electrical or mechanical performance.

Q: Are both parts RoHS compliant?

A: Yes. Both the SN74LS156D and SN74LS156DR are ROHS3 compliant and carry MSL Level 1 (Unlimited) moisture sensitivity rating, indicating no special moisture handling requirements during storage or assembly.