DM74LS393M Equivalent & Substitute Parts

Part Overview

The DM74LS393M is a binary counter IC featuring two independent 4-bit counters with negative edge triggering. Manufactured by onsemi in a 14-SOIC surface mount package, this component is classified as obsolete. Due to its obsolete status and limited availability from original sources, identifying equivalent substitute parts is essential for design continuity and procurement flexibility. Substitute parts must maintain identical functional specifications, electrical parameters, and package compatibility to ensure direct replacement capability.

Substiute Parts

DM74LS393M

onsemiIn Stock: 1452DM74LS393M Datasheet

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SN74LS393D

onsemiIn Stock: 1930SN74LS393D Datasheet

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SN74LS393DR

Texas InstrumentsIn Stock: 2122SN74LS393DR Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DM74LS393M are qualified based on the following critical parameters:

• Functional equivalence: Identical logic type (binary counter), element count (2), bit width (4 bits), direction (up), reset type (asynchronous), and trigger type (negative edge)
• Electrical compatibility: Matching voltage supply range (4.75 V ~ 5.25 V) and operating temperature range (0°C ~ 70°C)
• Package compatibility: Identical 14-SOIC surface mount package with 0.154" width (3.90mm)
• Count rate tolerance: Substitute parts operate at 35 MHz, which exceeds the original 25 MHz specification and is therefore compatible for applications designed for the DM74LS393M

The substitutes SN74LS393D and SN74LS393DR meet all functional and electrical requirements for direct replacement.

Parameter Comparison

Engineering Selection Recommendations

SN74LS393DR (Texas Instruments) is the preferred substitute for new designs and procurement. This part is currently active in production, ROHS3 compliant, and available in Tape & Reel packaging for automated assembly. The higher count rate (35 MHz) provides performance margin over the original specification.

SN74LS393D (onsemi) serves as an alternative substitute with identical functional specifications. This part remains obsolete but offers equivalent electrical performance. It is available in Tube packaging and is RoHS non-compliant, matching the compliance profile of the original DM74LS393M.

Both substitutes are electrically and functionally interchangeable with the DM74LS393M in applications operating within the specified voltage and temperature ranges.

Frequently Asked Questions (FAQ)

Q: Can SN74LS393D and SN74LS393DR be used interchangeably with DM74LS393M?

A: Yes. Both substitutes maintain identical functional specifications (2-element, 4-bit binary counter, negative edge trigger, asynchronous reset) and electrical parameters (4.75 V ~ 5.25 V supply, 0°C ~ 70°C operating range). The 14-SOIC package is identical across all three parts.

Q: What is the significance of the higher count rate in substitute parts?

A: The SN74LS393D and SN74LS393DR operate at 35 MHz compared to the DM74LS393M's 25 MHz. This higher specification is compatible with applications designed for the original part, as it provides additional performance margin without affecting functional behavior.

Q: Does packaging format affect substitution?

A: Packaging format (Tube for SN74LS393D, Tape & Reel for SN74LS393DR) affects procurement and assembly processes but does not impact electrical or functional compatibility. The physical 14-SOIC package dimensions are identical.

Q: What is the difference in RoHS compliance between these parts?

A: The DM74LS393M and SN74LS393D are RoHS non-compliant. The SN74LS393DR is ROHS3 compliant, making it suitable for applications with RoHS requirements. Selection depends on end-product compliance obligations.

Q: Which substitute should be selected for new production?

A: SN74LS393DR (Texas Instruments) is recommended for new production due to its active product status and ROHS3 compliance. SN74LS393D is suitable for legacy system maintenance where RoHS compliance is not required.