MM74HC4538MX Equivalent & Substitute Parts

Part Overview

The MM74HC4538MX is a monostable multivibrator logic IC manufactured by onsemi, housed in a 16-SOIC package with a propagation delay of 26 ns. This component is classified as obsolete, indicating that direct replacements or functionally equivalent alternatives are necessary for new designs or inventory replenishment. The 74HC4538 series provides dual independent monostable circuits with Schmitt trigger inputs, operating across a 2 V to 6 V supply range and supporting industrial temperature specifications.

Substiute Parts

MM74HC4538MX

onsemiIn Stock: 1369MM74HC4538MX Datasheet

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MC74HC4538ADG

onsemiIn Stock: 1226MC74HC4538ADG Datasheet

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MC74HC4538ADR2G

onsemiIn Stock: 15678MC74HC4538ADR2G Datasheet

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NLV74HC4538ADR2G

onsemiIn Stock: 3807NLV74HC4538ADR2G Datasheet

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74HC4538D,653

Nexperia USA Inc.In Stock: 230374HC4538D,653 Datasheet

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CD74HC4538M

Texas InstrumentsIn Stock: 1791CD74HC4538M Datasheet

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CD74HC4538M96

Texas InstrumentsIn Stock: 18296CD74HC4538M96 Datasheet

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CD74HC4538MT

Texas InstrumentsIn Stock: 4018CD74HC4538MT Datasheet

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CD74HC4538NSR

Texas InstrumentsIn Stock: 2696CD74HC4538NSR Datasheet

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CD74HC4538QM96G4Q1

Texas InstrumentsIn Stock: 4241CD74HC4538QM96G4Q1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the MM74HC4538MX is determined by the following critical parameters:

Primary Compatibility Criteria:

• Logic type: Monostable multivibrator
• Independent circuits: 2
• Package / Case: 16-SOIC form factor (0.154", 3.90mm Width)
• Voltage supply range: 2 V ~ 6 V minimum
• Output current capability: 5.2 mA minimum (both high and low)
• Mounting type: Surface mount

Secondary Compatibility Considerations:

• Propagation delay: Acceptable range up to 30 ns (main part: 26 ns)
• Schmitt trigger input: Preferred but not mandatory for all applications
• Operating temperature range: Minimum -40°C to 85°C coverage required
• Moisture sensitivity: MSL 1 (Unlimited) preferred

Substitute parts are grouped based on their adherence to these parameters. Parts with identical package geometry, electrical specifications, and functional characteristics are considered direct substitutes. Variations in propagation delay, temperature range, and product status are noted to support application-specific selection.

Parameter Comparison

Engineering Selection Recommendations

Tier 1 - Preferred Substitutes (Active Product Status):

MC74HC4538ADR2G (onsemi) and CD74HC4538M96 (Texas Instruments) are the primary recommendations. Both maintain active product status, ensuring long-term availability and supply chain stability. MC74HC4538ADR2G provides onsemi continuity with extended temperature range (-55°C ~ 125°C) and 30 ns propagation delay. CD74HC4538M96 offers superior propagation delay performance (21 ns) with active status and highest inventory availability (18213 Pcs).

Tier 2 - Secondary Substitutes (Active Status, Package Considerations):

74HC4538D,653 (Nexperia) and CD74HC4538QM96G4Q1 (Texas Instruments) are active alternatives. The Nexperia part provides the fastest propagation delay (25 ns) but lacks Schmitt trigger input. CD74HC4538QM96G4Q1 includes automotive-grade qualification (AEC-Q100) suitable for extended temperature applications (-40°C ~ 125°C).

Tier 3 - Limited Availability (Last Time Buy / Obsolete Status):

CD74HC4538MT, CD74HC4538M, MC74HC4538ADG, and NLV74HC4538ADR2G are available but face supply constraints. NLV74HC4538ADR2G includes automotive qualification (AEC-Q100) for specialized applications. These parts should be considered only when Tier 1 and Tier 2 options are insufficient.

Package Compatibility Note:

CD74HC4538NSR uses a 16-SOIC package with 0.209" width, differing from the standard 0.154" width of other substitutes. This variation may require PCB layout verification before selection.

Frequently Asked Questions (FAQ)

Q: Can I directly replace MM74HC4538MX with any 74HC4538 variant?

A: Direct replacement requires matching the 16-SOIC (0.154", 3.90mm Width) package form factor, 2 V ~ 6 V supply voltage range, and dual independent monostable circuit configuration. Propagation delay variations (21 ns to 30 ns) are acceptable for most applications. Verify Schmitt trigger input requirements for your specific circuit design.

Q: What is the difference between onsemi, Texas Instruments, and Nexperia versions?

A: All three manufacturers produce functionally equivalent 74HC4538 monostable multivibrators within the same logic family. Propagation delays vary slightly (onsemi: 26-30 ns, Texas Instruments: 21 ns, Nexperia: 25 ns). Texas Instruments parts offer the fastest performance and highest current inventory. Nexperia parts lack Schmitt trigger input on the 74HC4538D,653 variant. Select based on availability, delivery timeline, and performance requirements.

Q: Is the CD74HC4538NSR compatible with my design if it uses a different package width?

A: CD74HC4538NSR uses a 16-SOIC package with 0.209" width compared to the standard 0.154" width. While the pin count and electrical specifications remain compatible, the physical footprint differs. PCB layout and mechanical clearance must be verified before substitution. If space constraints exist, select alternatives with the standard 0.154" width.

Q: What does "Last Time Buy" product status mean?

A: Last Time Buy indicates the manufacturer has announced end-of-life for that specific part number. Existing inventory is available for purchase, but no future production is planned. CD74HC4538M and CD74HC4538MT are in this status. For long-term supply security, prioritize Active status parts such as CD74HC4538M96 or MC74HC4538ADR2G.

Q: Do I need Schmitt trigger input for my application?

A: Schmitt trigger input provides noise immunity and hysteresis for signal conditioning. Most 74HC4538 substitutes include this feature. The Nexperia 74HC4538D,653 variant omits Schmitt trigger input. If your circuit design relies on Schmitt trigger functionality, avoid this part and select alternatives with confirmed Schmitt trigger input.

Q: What is the significance of AEC-Q100 qualification?

A: AEC-Q100 qualification indicates automotive-grade reliability testing and is required for automotive applications. NLV74HC4538ADR2G and CD74HC4538QM96G4Q1 carry this certification. If your application is non-automotive, standard industrial-grade parts are sufficient. Automotive-qualified parts may have longer lead times and higher costs.