SN74LS126AD Equivalent & Substitute Parts

Part Overview

The SN74LS126AD is a non-inverting buffer IC manufactured by Texas Instruments, designed for logic signal buffering applications. It features 4 elements with 1 bit per element and 3-state output capability, housed in a 14-SOIC surface mount package. The device operates within a 4.75V to 5.25V supply voltage range and is rated for 0°C to 70°C operating temperature.

The SN74LS126AD carries a Last Time Buy product status, indicating that Texas Instruments has discontinued active production. This status necessitates identifying equivalent substitute parts to ensure design continuity and procurement availability for new builds and ongoing production requirements.

Substiute Parts

SN74LS126AD

Texas InstrumentsIn Stock: 943SN74LS126AD Datasheet

Current PartRFQ

SN74LS126ADR

Texas InstrumentsIn Stock: 3105SN74LS126ADR Datasheet

MFR RecommendedRFQ

SN74LS125AD

Texas InstrumentsIn Stock: 2094SN74LS125AD Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS126AD are identified based on strict electrical and mechanical parameter equivalence. The substitution criteria are:

• Logic Type: Buffer, Non-Inverting
• Number of Elements: 4
• Number of Bits per Element: 1
• Output Type: 3-State
• Current Specifications: 2.6mA (Output High), 24mA (Output Low)
• Voltage Supply Range: 4.75V ~ 5.25V
• Operating Temperature Range: 0°C ~ 70°C
• Package Type: 14-SOIC surface mount
• Physical Dimensions: 0.154" width, 3.90mm width

Two substitute parts meet these criteria and are grouped as follows:

MFR Recommended Substitute (Packaging Variant): SN74LS126ADR differs only in packaging format (Tape & Reel versus Tube) while maintaining identical electrical specifications and Active product status.

Parametric Equivalent Substitute (Base Product Variant): SN74LS125AD represents an alternative base product number within the same 74LS series, maintaining all critical electrical parameters and functional characteristics.

Parameter Comparison

Engineering Selection Recommendations

SN74LS126ADR is the primary substitute for the SN74LS126AD. Both parts are manufactured by Texas Instruments with identical electrical specifications, functional characteristics, and compliance certifications (ROHS3 Compliant, MSL 1). The SN74LS126ADR maintains Active product status, ensuring long-term availability and supply chain stability. The only difference is packaging format: SN74LS126ADR is supplied in Tape & Reel format, which is standard for automated assembly processes, whereas the original SN74LS126AD is supplied in Tube format.

SN74LS125AD is a parametric equivalent substitute that meets all critical electrical and functional requirements. It operates identically to the SN74LS126AD within the specified voltage, current, temperature, and output characteristics. However, the SN74LS125AD carries undefined Moisture Sensitivity Level and unspecified RoHS status, which may require verification against specific design compliance requirements. The SN74LS125AD is supplied in Bulk packaging format.

For applications requiring maximum compliance certainty and supply continuity, SN74LS126ADR is the recommended selection. For applications where compliance documentation is already established or where bulk packaging is acceptable, SN74LS125AD provides a viable alternative.

Frequently Asked Questions (FAQ)

Q: Can SN74LS126ADR be used as a direct replacement for SN74LS126AD?

A: Yes. SN74LS126ADR is electrically and functionally identical to SN74LS126AD. Both parts share the same logic type, element count, output characteristics, voltage supply range, operating temperature range, and 14-SOIC package dimensions. The difference is packaging format: SN74LS126ADR uses Tape & Reel format while SN74LS126AD uses Tube format. Both are suitable for PCB assembly.

Q: What is the difference between SN74LS126AD and SN74LS125AD?

A: Both parts are non-inverting buffers with 4 elements, 1 bit per element, and 3-state outputs. They share identical electrical specifications: 2.6mA/24mA output current, 4.75V–5.25V supply voltage, and 0°C–70°C operating temperature. The primary difference is the base product number (126 versus 125). SN74LS125AD has undefined MSL and unspecified RoHS status, whereas SN74LS126AD is ROHS3 Compliant with MSL 1.

Q: Why is the SN74LS126AD marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued active production of this part number. Existing inventory may be available from distributors, but no new manufacturing runs are planned. Substitutes with Active status, such as SN74LS126ADR, ensure continued availability for future production needs.

Q: Are there any pinout differences between these substitute parts?

A: No. All three parts (SN74LS126AD, SN74LS126ADR, and SN74LS125AD) use the 14-SOIC package with identical pin assignments and functional pinout. They are pin-compatible and can be used interchangeably on the same PCB layout.

Q: Which substitute should I choose for new designs?

A: SN74LS126ADR is recommended for new designs. It maintains Active product status, ensuring long-term supply availability, and carries full ROHS3 compliance and MSL 1 certification. The Tape & Reel packaging is standard for automated assembly processes.

Q: Can I mix packaging formats in the same production run?

A: Packaging format selection depends on assembly process requirements. Tape & Reel format (SN74LS126ADR) is optimized for automated pick-and-place assembly. Tube format (SN74LS126AD) and Bulk format (SN74LS125AD) are suitable for manual assembly or alternative handling processes. Verify with your assembly partner regarding format compatibility with your production equipment.