MM74HC240SJX Equivalent & Substitute Parts

Part Overview

The MM74HC240SJX is a 2-element, 4-bit inverting buffer with 3-state output logic IC manufactured by onsemi in a 20-SOP package. This component operates across a 2V to 6V supply voltage range with output currents of 7.8mA for both high and low states, suitable for general-purpose logic buffering and signal inversion applications.

The MM74HC240SJX is classified as obsolete. Equivalent and substitute parts are necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements. Multiple manufacturers produce functionally compatible alternatives within the 74HC240 logic family.

Substiute Parts

MM74HC240SJX

onsemiIn Stock: 888MM74HC240SJX Datasheet

Current PartRFQ

SN74HC240NSR

Texas InstrumentsIn Stock: 14744SN74HC240NSR Datasheet

DirectRFQ

CD74HC240M

Texas InstrumentsIn Stock: 1203CD74HC240M Datasheet

SimilarRFQ

CD74HC240M96

Texas InstrumentsIn Stock: 5087CD74HC240M96 Datasheet

SimilarRFQ

SN74HC240DBR

Texas InstrumentsIn Stock: 4959SN74HC240DBR Datasheet

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SN74HC240DW

Texas InstrumentsIn Stock: 5330SN74HC240DW Datasheet

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SN74HC240DWR

Texas InstrumentsIn Stock: 3100SN74HC240DWR Datasheet

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SN74HC240ANSR

Texas InstrumentsIn Stock: 2965SN74HC240ANSR Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the MM74HC240SJX is determined by strict adherence to the following electrical and mechanical parameters:

Core Electrical Parameters (Must Match):

• Logic Type: Buffer, Inverting
• Number of Elements: 2
• Number of Bits per Element: 4
• Output Type: 3-State
• Current - Output High, Low: 7.8mA, 7.8mA
• Voltage - Supply: 2V ~ 6V
• Base Product Number: 74HC240

Mechanical Parameters (Allowable Variations):

• Package / Case: 20-SOIC variants (0.209" or 0.295" width) and 20-SSOP
• Supplier Device Package: 20-SOP, 20-SO, 20-SOIC, 20-SSOP

Operating Temperature Considerations:

• Primary operating range: -40°C ~ 85°C (TA)
• Extended range alternatives: -55°C ~ 125°C (TA) are acceptable for applications requiring broader temperature performance

Compliance & Status:

• RoHS3 Compliant (required)
• Moisture Sensitivity Level 1 (required)
• Product Status: Active or Last Time Buy preferred; Discontinued at DiGi Electronics acceptable with inventory verification

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

SN74HC240NSR and SN74HC240ANSR are direct electrical and mechanical equivalents with Active product status. Both are manufactured by Texas Instruments in 20-SO packaging, matching the original 0.209" width specification. These parts maintain identical electrical performance and operating temperature range (-40°C ~ 85°C) as the MM74HC240SJX.

Secondary Substitutes (Package Variation):

SN74HC240DWR and SN74HC240DW are functionally equivalent with identical electrical specifications but use 20-SOIC packaging (0.295" width). Both maintain the -40°C ~ 85°C operating range. SN74HC240DWR carries Active status; SN74HC240DW is Discontinued at DiGi Electronics but remains available through inventory channels.

Extended Temperature Alternatives:

CD74HC240M96 and CD74HC240M extend the operating temperature range to -55°C ~ 125°C while maintaining all electrical parameters. CD74HC240M96 is Active; CD74HC240M is Last Time Buy. These are suitable for applications requiring broader thermal performance.

Package Consideration:

SN74HC240DBR provides a compact 20-SSOP alternative (0.209" width) with Active status, suitable for space-constrained designs while maintaining standard operating temperature range.

All substitute parts are ROHS3 Compliant with MSL 1 rating, ensuring regulatory and environmental compatibility with the original specification.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with a different package type?

A: Yes, provided the package maintains the same pin count (20 pins) and electrical connectivity. The 20-SOP, 20-SO, 20-SOIC, and 20-SSOP packages are mechanically and electrically compatible for the 74HC240 logic family. PCB layout and footprint design must accommodate the specific package dimensions.

Q: What is the difference between 20-SOIC (0.209" width) and 20-SOIC (0.295" width)?

A: These designations refer to the package body width. The 0.209" width (narrow body) is equivalent to 20-SO packaging, while 0.295" width (wide body) is standard 20-SOIC. Both maintain identical pin pitch and electrical performance. Verify PCB footprint compatibility before substitution.

Q: Are extended temperature range parts (CD74HC240M, CD74HC240M96) drop-in replacements?

A: Electrically yes. The extended -55°C ~ 125°C range encompasses the original -40°C ~ 85°C specification. However, verify PCB footprint compatibility, as these parts use 20-SOIC (0.295" width) packaging rather than the original 20-SOP.

Q: Why is the MM74HC240SJX obsolete?

A: The MM74HC240SJX is classified as obsolete by onsemi. Multiple active alternatives from Texas Instruments provide equivalent functionality with improved supply chain availability and product lifecycle support.

Q: Which substitute offers the best long-term availability?

A: SN74HC240NSR, SN74HC240ANSR, and CD74HC240M96 carry Active product status from Texas Instruments, indicating ongoing production and supply chain support. These are recommended for new designs and long-term production requirements.

Q: Do all substitutes meet RoHS3 compliance?

A: Yes. All listed substitute parts are ROHS3 Compliant with MSL 1 rating, matching the original specification and regulatory requirements.