SN74LS266DR Equivalent & Substitute Parts

Part Overview

The SN74LS266DR is a 4-channel XNOR (Exclusive NOR) logic gate IC with open collector output configuration, housed in a 14-SOIC surface mount package. This component is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and procurement continuity. The part operates within the 74LS logic family standard, making direct substitution possible with compatible variants that maintain electrical and mechanical specifications.

Substiute Parts

SN74LS266DR

Texas InstrumentsIn Stock: 833SN74LS266DR Datasheet

Current PartRFQ

SN74LS266D

Texas InstrumentsIn Stock: 1399SN74LS266D Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS266DR is determined by strict equivalence across the following critical parameters:

• Logic Function: XNOR gate with 4 channels, 2 inputs per channel
• Output Configuration: Open collector topology
• Electrical Specifications: Supply voltage range 4.75V ~ 5.25V, output current 8mA maximum, propagation delay 30ns @ 5V with 15pF load
• Input Thresholds: Logic low 0.8V, logic high 2V
• Package Format: 14-SOIC surface mount package with identical physical dimensions
• Environmental Compliance: ROHS3 compliance and MSL Level 1 rating

The SN74LS266D qualifies as a direct substitute based on complete alignment with these parameters. The primary distinction is product status: the SN74LS266DR is obsolete, while the SN74LS266D remains active in production.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS266D is the appropriate substitute for the obsolete SN74LS266DR. Both components are manufactured by Texas Instruments and maintain identical electrical and mechanical specifications. The SN74LS266D offers the advantage of active product status, ensuring continued availability and manufacturing support. Both parts carry ROHS3 compliance certification and MSL Level 1 rating, confirming environmental and moisture handling equivalence. Pin-for-pin compatibility and package dimensional equivalence enable direct board-level substitution without design modification.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS266D replace the SN74LS266DR in existing designs?

A: Yes. The SN74LS266D is a direct pin-for-pin and functionally equivalent substitute. Electrical specifications, package dimensions, and pin assignments are identical. No circuit redesign is required.

Q: What is the primary reason for substitution?

A: The SN74LS266DR is classified as obsolete. The SN74LS266D is the active production equivalent from the same manufacturer, ensuring long-term availability and supply chain continuity.

Q: Are there any differences in compliance or environmental ratings?

A: No. Both parts carry identical ROHS3 compliance status and MSL Level 1 moisture sensitivity rating. Environmental and regulatory requirements are equivalent.

Q: Does the package format differ between these parts?

A: No. Both components use the 14-SOIC surface mount package with identical physical dimensions (0.154" width, 3.90mm). PCB footprints are interchangeable.

Q: What are the critical electrical parameters that define substitution eligibility?

A: Substitution is based on matching logic function (4-channel XNOR), output configuration (open collector), supply voltage range (4.75V ~ 5.25V), output current (8mA), input thresholds (0.8V low, 2V high), and propagation delay (30ns @ 5V, 15pF load).

Q: Is the SN74LS266D available in the same packaging format?

A: Yes. The SN74LS266D is supplied in tube packaging, maintaining the 14-SOIC surface mount configuration. Packaging format does not affect electrical or mechanical compatibility.