MM74HCT240N Equivalent & Substitute Parts

Part Overview

The MM74HCT240N is a logic buffer IC with inverting functionality, manufactured by onsemi in a 20-DIP package. This device features 2 elements with 4 bits per element and 3-state output capability, operating across a 4.5V to 5.5V supply range. The part is classified as obsolete, making equivalent substitutes necessary for ongoing design support and procurement.

Substiute Parts

MM74HCT240N

onsemiIn Stock: 10965MM74HCT240N Datasheet

Current PartRFQ

CD74HCT164E

Texas InstrumentsIn Stock: 1843CD74HCT164E Datasheet

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CD74HCT240E

Harris CorporationIn Stock: 50242CD74HCT240E Datasheet

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SN74HCT240N

Texas InstrumentsIn Stock: 2211SN74HCT240N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the MM74HCT240N is determined by strict alignment of the following critical parameters:

• Logic Type: Buffer, Inverting (functional equivalence)
• Number of Elements: 2 (circuit configuration match)
• Number of Bits per Element: 4 (data width match)
• Output Type: 3-State (control capability match)
• Voltage - Supply: 4.5V ~ 5.5V (power compatibility)
• Package / Case: 20-DIP (0.300", 7.62mm) (physical and pin compatibility)
• Mounting Type: Through Hole (assembly compatibility)

Substitute parts must satisfy all these parameters to ensure direct functional and physical replacement without circuit redesign.

Parameter Comparison

Engineering Selection Recommendations

CD74HCT240E (Harris Corporation): This part matches all critical functional and physical parameters with the MM74HCT240N. However, it carries obsolete product status and RoHS non-compliance, limiting its suitability for new designs or regulated applications.

SN74HCT240N (Texas Instruments): This part provides full functional and physical equivalence to the MM74HCT240N across all critical parameters. The SN74HCT240N maintains active product status and ROHS3 compliance, making it the preferred substitute for ongoing procurement and new design implementations. Operating temperature range matches the original specification (-40°C ~ 85°C).

Frequently Asked Questions (FAQ)

Q: Can CD74HCT164E substitute for MM74HCT240N? A: No. CD74HCT164E is a shift register with different logic type, element count, and bit configuration. It operates in 14-DIP package, not 20-DIP. This part does not meet substitution criteria.

Q: What is the primary difference between CD74HCT240E and SN74HCT240N? A: Both parts are functionally equivalent to MM74HCT240N. The key distinction is product status: CD74HCT240E is obsolete with RoHS non-compliance, while SN74HCT240N is active with ROHS3 compliance. For new applications, SN74HCT240N is the recommended choice.

Q: Are there output current differences between substitutes? A: Yes. MM74HCT240N specifies 7.2mA output current (high and low), while both CD74HCT240E and SN74HCT240N specify 6mA. This difference is within typical design margins for 74HCT logic family applications but should be verified against specific load requirements.

Q: Can these parts be used interchangeably in existing designs? A: Yes, for designs currently using MM74HCT240N. All substitute parts share identical pin configuration, package dimensions, and functional behavior. Direct socket replacement is possible without circuit modification.

Q: What is the operating temperature range consideration? A: MM74HCT240N and SN74HCT240N both operate -40°C ~ 85°C. CD74HCT240E extends to -55°C ~ 125°C. Select based on your application's thermal requirements.