DM74AS640WMX Equivalent & Substitute Parts

Part Overview

The DM74AS640WMX is a logic transceiver IC manufactured by onsemi, featuring inverting functionality with 1 element and 8 bits per element. The device provides 3-state output capability and operates within a 4.5V to 5.5V supply voltage range. This part is classified as obsolete, making identification of suitable substitute components essential for ongoing system support and new design implementations.

Substiute Parts

DM74AS640WMX

onsemiIn Stock: 7443DM74AS640WMX Datasheet

Current PartRFQ

SN74AS640NSR

Texas InstrumentsIn Stock: 888SN74AS640NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DM74AS640WMX is determined by strict equivalence across the following critical parameters:

• Logic Function: Transceiver, Inverting configuration with identical element and bit-per-element count (1 element, 8 bits per element)
• Output Architecture: 3-State output capability
• Electrical Specifications: Matching output current ratings (15mA high, 64mA low) and supply voltage range (4.5V ~ 5.5V)
• Operating Conditions: Identical temperature range (0°C ~ 70°C)
• Package Type: 20-SOIC surface mount package
• Series Compatibility: 74AS logic family

The SN74AS640NSR from Texas Instruments meets all these criteria and qualifies as a direct substitute.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS640NSR is a qualified substitute for the DM74AS640WMX based on functional and electrical equivalence. The substitute part maintains active product status with Texas Instruments, ensuring continued availability and supply chain reliability. The SN74AS640NSR carries ROHS3 compliance certification, providing environmental regulatory advantage over the original part.

Both components share identical electrical performance specifications and operate within the same parameter envelope. The package footprint difference (0.295" versus 0.209" width) requires PCB layout verification to confirm mechanical compatibility in existing designs.

Frequently Asked Questions (FAQ)

Q: Can the SN74AS640NSR directly replace the DM74AS640WMX in existing designs?

A: Electrical substitution is valid based on matching logic function, output type, current ratings, and supply voltage specifications. Physical PCB compatibility must be verified due to package width variation (0.295" versus 0.209" 20-SOIC).

Q: What are the key parameters that define substitution eligibility?

A: Substitution requires matching series (74AS), logic type (Transceiver, Inverting), element count (1), bits per element (8), output type (3-State), current ratings (15mA/64mA), supply voltage (4.5V ~ 5.5V), temperature range (0°C ~ 70°C), and package type (20-SOIC).

Q: Does the product status difference affect substitution?

A: The DM74AS640WMX is obsolete while the SN74AS640NSR is active. Active status ensures ongoing availability and manufacturing support for the substitute part.

Q: Are there compliance differences between these parts?

A: The SN74AS640NSR carries ROHS3 compliance certification. Both parts maintain MSL 1 (Unlimited) moisture sensitivity rating and REACH Unaffected status.

Q: What should be verified before implementing the substitute part?

A: Confirm PCB footprint compatibility with the 20-SOIC package width specification. Verify that circuit board layout accommodates the dimensional difference between the original and substitute packages.