SN74F521DW Equivalent & Substitute Parts

Part Overview

The SN74F521DW is an 8-bit magnitude comparator with identity output (A=B) manufactured by Texas Instruments. This logic IC operates in the active-low output configuration and is housed in a 20-SOIC surface-mount package. The SN74F521DW is classified as Last Time Buy, indicating end-of-life status. Identifying equivalent substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications requiring 8-bit identity comparison functionality.

Substiute Parts

SN74F521DW

Texas InstrumentsIn Stock: 2702SN74F521DW Datasheet

Current PartRFQ

SN74F521DWR

Texas InstrumentsIn Stock: 3943SN74F521DWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74F521DW are determined by strict equivalence across the following critical parameters:

• Functional Identity: 8-bit magnitude comparator with A=B output function
• Output Logic Level: Active-low output configuration
• Electrical Specifications: Supply voltage 4.5V ~ 5.5V, output current 1mA/20mA, propagation delay 10ns @ 5V, 50pF
• Package Compatibility: 20-SOIC surface-mount package (0.295", 7.50mm width)
• Operating Temperature Range: 0°C ~ 70°C
• Compliance Standards: ROHS3 compliant, REACH unaffected

The SN74F521DWR qualifies as a direct substitute based on identical electrical characteristics, functional specifications, and package configuration. The primary distinction is packaging format (Cut Tape & Digi-Reel versus Tube) and product status (Active versus Last Time Buy).

Parameter Comparison

Engineering Selection Recommendations

The SN74F521DWR is the direct substitute for the SN74F521DW. Both parts are manufactured by Texas Instruments and maintain identical electrical and functional specifications. The SN74F521DWR carries Active product status, ensuring continued availability and support, whereas the SN74F521DW is designated Last Time Buy. For new designs or production continuity, the SN74F521DWR is the appropriate selection. Both parts meet ROHS3 compliance and REACH requirements, supporting regulatory obligations in manufacturing environments.

Frequently Asked Questions (FAQ)

Q: Can the SN74F521DWR be used as a direct replacement for the SN74F521DW?

A: Yes. The SN74F521DWR is electrically and functionally identical to the SN74F521DW. Both parts share the same 8-bit identity comparator architecture, active-low output configuration, supply voltage range (4.5V ~ 5.5V), propagation delay (10ns @ 5V, 50pF), and 20-SOIC package footprint. The primary difference is product status and packaging format.

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

A: Tube packaging is used for lower-volume orders and manual handling, while Cut Tape & Digi-Reel packaging is optimized for automated assembly processes and higher-volume production. Both formats contain identical components; the difference is in delivery and handling method.

Q: Why is the SN74F521DW marked as Last Time Buy?

A: Last Time Buy designation indicates the manufacturer is discontinuing production. This status necessitates transition to active alternatives such as the SN74F521DWR to maintain long-term supply chain stability.

Q: Are there any pin-compatibility or footprint differences between these parts?

A: No. Both the SN74F521DW and SN74F521DWR use the identical 20-SOIC package with 0.295" width (7.50mm). Pin assignments, signal functions, and PCB footprints are identical.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the SN74F521DW and SN74F521DWR are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic component manufacturing and distribution.