DM74ALS521WM Equivalent & Substitute Parts

Part Overview

The DM74ALS521WM is an 8-bit magnitude comparator with active low output (A=B function) manufactured by onsemi in a 20-SOIC surface mount package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The part operates within the 4.5V to 5.5V supply voltage range and is suitable for digital logic applications requiring identity comparison functionality.

Substiute Parts

DM74ALS521WM

onsemiIn Stock: 917DM74ALS521WM Datasheet

Current PartRFQ

SN74ALS521DW

Texas InstrumentsIn Stock: 2074SN74ALS521DW Datasheet

DirectRFQ

SN74ALS521DWR

Texas InstrumentsIn Stock: 2931SN74ALS521DWR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DM74ALS521WM are qualified based on strict electrical and mechanical parameter matching:

Critical Parameters for Substitution:

• 8-bit identity comparator function with A=B output
• Active low output logic
• 4.5V to 5.5V supply voltage compatibility
• 20ns maximum propagation delay at 5V with 50pF load
• 2.6mA and 24mA output current specifications
• 20-SOIC surface mount package (0.295", 7.50mm width)
• Operating temperature range 0°C to 70°C

All substitute parts listed maintain identical electrical performance and mechanical compatibility with the original DM74ALS521WM specification.

Parameter Comparison

Engineering Selection Recommendations

SN74ALS521DWR (Texas Instruments) - Recommended for New Designs

The SN74ALS521DWR is the preferred substitute for new production and design implementations. This part carries Active product status, ensuring long-term availability and supply chain stability. It is ROHS3 compliant and supplied in Tape & Reel (TR) packaging, which is standard for automated assembly processes. With 2897 pieces in current inventory, this part provides immediate availability for production requirements.

SN74ALS521DW (Texas Instruments) - Alternative Option

The SN74ALS521DW serves as an alternative substitute with Last Time Buy status. This part is ROHS3 compliant and supplied in Tube packaging. With 2044 pieces in inventory, it remains available for applications where Tape & Reel packaging is not required. This part is suitable for lower-volume production or prototype applications.

Substitution Basis

Both Texas Instruments substitutes maintain complete electrical and mechanical equivalence to the obsolete DM74ALS521WM. All critical parameters—including 8-bit comparison function, active low output, supply voltage range, propagation delay, output current specifications, and 20-SOIC package dimensions—are identical. The substitution is direct with no circuit modifications required.

Frequently Asked Questions (FAQ)

Q: Can SN74ALS521DW and SN74ALS521DWR be used interchangeably with DM74ALS521WM?

A: Yes. Both Texas Instruments parts are direct electrical and mechanical equivalents. The difference between them is packaging format: SN74ALS521DW uses Tube packaging, while SN74ALS521DWR uses Tape & Reel packaging. Selection depends on assembly process requirements.

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

A: Tube packaging is suitable for manual assembly and lower-volume applications. Tape & Reel packaging is designed for automated pick-and-place assembly systems used in high-volume production. Both contain identical components with the same electrical specifications.

Q: Is the 20-SOIC package dimension identical across all three parts?

A: Yes. All three parts use the 20-SOIC package with 0.295" (7.50mm) width. PCB footprints and assembly processes are identical.

Q: Are there any compliance differences between the substitute parts?

A: The Texas Instruments substitutes (SN74ALS521DW and SN74ALS521DWR) are ROHS3 compliant. All three parts are REACH unaffected and carry the same ECCN (EAR99) and HTSUS (8542.39.0001) classifications.

Q: Which substitute should be selected for new production?

A: SN74ALS521DWR is recommended for new production due to its Active product status and Tape & Reel packaging compatibility with automated assembly. SN74ALS521DW is suitable where Tube packaging meets assembly requirements.