SN74LS642NSR Equivalent & Substitute Parts

Part Overview

The SN74LS642NSR is an active logic transceiver IC manufactured by Texas Instruments, designed for inverting signal conversion with 1 element and 8 bits per element. The device features open collector output configuration and operates within the 4.75V to 5.25V supply voltage range. This part is supplied in Tape & Reel packaging with a 20-SO package format. Finding equivalent and substitute parts is necessary to address supply chain flexibility, packaging preferences, and inventory optimization while maintaining functional and electrical compatibility.

Substiute Parts

SN74LS642NSR

Texas InstrumentsIn Stock: 2459SN74LS642NSR Datasheet

Current PartRFQ

SN74LS642DW

Texas InstrumentsIn Stock: 2228SN74LS642DW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS642NSR is determined by strict equivalence across the following critical parameters:

• Logic type and functional configuration (Transceiver, Inverting)
• Number of elements (1) and bits per element (8)
• Output type (Open Collector)
• Output current specification (24mA low)
• Supply voltage range (4.75V ~ 5.25V)
• Operating temperature range (0°C ~ 70°C)
• Series designation (74LS)
• Mounting type (Surface Mount)
• Compliance certifications (ROHS3, REACH Unaffected)

The SN74LS642DW qualifies as a manufacturer-recommended substitute based on identical electrical specifications and functional characteristics. The primary distinction between these parts is packaging format: the main part uses Tape & Reel (TR) packaging in 20-SO format, while the substitute uses Tube packaging in 20-SOIC format. Both package types are surface mount configurations with compatible pinouts and mechanical footprints suitable for the same PCB applications.

Parameter Comparison

Engineering Selection Recommendations

Both the SN74LS642NSR and SN74LS642DW are active products from Texas Instruments with identical electrical and functional specifications. Selection between these parts should be based on packaging and supply chain requirements:

The SN74LS642NSR in Tape & Reel format is suitable for high-volume automated assembly operations where continuous reel feeding is required. The SN74LS642DW in Tube packaging is appropriate for lower-volume production runs, manual assembly processes, or applications where tube packaging is preferred for handling and storage.

Both parts maintain full ROHS3 compliance and REACH unaffected status, ensuring regulatory compatibility across industrial and commercial applications. The MSL rating of 1 (Unlimited) indicates no moisture sensitivity constraints for either part.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS642DW directly replace the SN74LS642NSR in my circuit?

A: Yes. Both parts are electrically and functionally identical with matching pinouts, supply voltage requirements, output current specifications, and operating temperature ranges. The difference is packaging format only.

Q: What is the difference between Tape & Reel and Tube packaging?

A: Tape & Reel packaging supplies components on a continuous reel suitable for automated pick-and-place assembly. Tube packaging supplies components in a plastic tube suitable for manual handling and lower-volume assembly. Both formats contain the same component with identical electrical performance.

Q: Are there any PCB footprint differences between these parts?

A: Both parts use 20-SOIC surface mount packages. While the package width specifications differ slightly (0.209" versus 0.295"), both are standard 20-SOIC configurations compatible with the same PCB footprint patterns used in modern surface mount design.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the SN74LS642NSR and SN74LS642DW are ROHS3 compliant and REACH unaffected, meeting the same regulatory requirements for industrial and commercial applications.

Q: Which part should I select for my design?

A: Selection depends on your manufacturing process. Choose SN74LS642NSR for automated high-volume assembly with reel feeding capability. Choose SN74LS642DW for manual assembly, lower-volume production, or when tube packaging is preferred for your supply chain.