74ACTQ240QSCX Equivalent & Substitute Parts

Part Overview

The 74ACTQ240QSCX is a buffer inverting logic IC manufactured by onsemi, featuring 2 elements with 4 bits per element and 3-state output capability. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The part operates within a 4.5V to 5.5V supply voltage range and is rated for -40°C to 85°C operating temperature. Identifying compatible substitutes ensures design flexibility and supply chain resilience.

Substiute Parts

74ACTQ240QSCX

onsemiIn Stock: 87574ACTQ240QSCX Datasheet

Current PartRFQ

CY74FCT240ATQCT

Texas InstrumentsIn Stock: 5660CY74FCT240ATQCT Datasheet

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SN74ACT240DBR

Texas InstrumentsIn Stock: 3146SN74ACT240DBR Datasheet

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SN74ACT240PW

Texas InstrumentsIn Stock: 1955SN74ACT240PW Datasheet

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SN74ACT240PWR

Texas InstrumentsIn Stock: 2935SN74ACT240PWR Datasheet

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SN74ACT240PWRG4

Texas InstrumentsIn Stock: 868SN74ACT240PWRG4 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74ACTQ240QSCX is determined by the following critical parameters:

• Logic Type: Buffer, Inverting (2 elements, 4 bits per element)
• Output Type: 3-State
• Voltage Supply Range: 4.5V ~ 5.5V or compatible overlap
• Operating Temperature: -40°C ~ 85°C (TA)
• Mounting Type: Surface Mount
• Package footprint compatibility: 20-pin QSOP/SSOP/TSSOP variants with 0.154" to 0.209" width tolerance

Substitute parts must maintain functional equivalence in logic configuration, output drive capability, and thermal operating range. Package variants (QSOP, SSOP, TSSOP) are acceptable substitutes provided PCB layout accommodates the physical dimensions.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Active Product Status):

SN74ACT240PWR and SN74ACT240DBR are the preferred substitutes. Both are manufactured by Texas Instruments with Active product status, ensuring long-term availability and supply continuity. SN74ACT240PWR is available in 20-TSSOP packaging with Cut Tape and Digi-Reel packaging options. SN74ACT240DBR is available in 20-SSOP packaging. Both maintain identical electrical specifications to the 74ACTQ240QSCX (24mA output current, 4.5V ~ 5.5V supply voltage, -40°C ~ 85°C operating range) and are ROHS3 compliant.

Secondary Substitute (Enhanced Output Current):

CY74FCT240ATQCT is a Texas Instruments 74FCT series part with higher output current capability (32mA high, 64mA low) compared to the 74ACT series. This part is Active and ROHS3 compliant. The supply voltage range is narrower (4.75V ~ 5.25V), which overlaps with the 74ACTQ240QSCX operating range. The 20-SSOP package footprint matches the main part at 0.154" width. This substitute is suitable for applications requiring enhanced drive capability.

Discontinued Parts:

SN74ACT240PW and SN74ACT240PWRG4 are marked as Discontinued at DiGi Electronics and should not be selected for new designs requiring long-term component availability.

Package Considerations:

The 74ACTQ240QSCX uses 20-LSSOP packaging. Substitutes are available in 20-SSOP and 20-TSSOP variants. PCB layout must accommodate the physical differences: 20-SSOP (0.209" width) is wider than the original, while 20-TSSOP (0.173" width) is narrower. Verify footprint compatibility before design implementation.

Frequently Asked Questions (FAQ)

Q: Can SN74ACT240DBR replace 74ACTQ240QSCX directly?

A: SN74ACT240DBR is functionally equivalent in logic configuration, output type, and electrical specifications. However, the package footprint differs: 20-SSOP (0.209" width) versus 20-LSSOP (0.154" width). PCB layout modification is required to accommodate the wider package.

Q: What is the difference between CY74FCT240ATQCT and SN74ACT240PWR?

A: Both are 3-state inverting buffers with 2 elements and 4 bits per element. CY74FCT240ATQCT provides higher output current (32mA/64mA) compared to SN74ACT240PWR (24mA/24mA). CY74FCT240ATQCT has a narrower supply voltage range (4.75V ~ 5.25V) versus SN74ACT240PWR (4.5V ~ 5.5V). Select CY74FCT240ATQCT for applications requiring enhanced drive capability within the narrower voltage window.

Q: Is the 74ACTQ240QSCX still available for procurement?

A: The 74ACTQ240QSCX is classified as Obsolete. Active substitutes such as SN74ACT240PWR and SN74ACT240DBR are recommended for new designs and ongoing procurement.

Q: What packaging options are available for substitutes?

A: Substitutes are available in three 20-pin surface mount packages: 20-LSSOP (0.154" width, matching the original), 20-SSOP (0.209" width, wider), and 20-TSSOP (0.173" width, narrower). Verify PCB footprint compatibility before selection.

Q: Are all substitute parts ROHS3 compliant?

A: All Texas Instruments substitutes listed are ROHS3 compliant. The original 74ACTQ240QSCX RoHS status is not specified in the provided data.

Q: What is the moisture sensitivity difference between the main part and substitutes?

A: The 74ACTQ240QSCX has MSL 1 (Unlimited). CY74FCT240ATQCT has MSL 2 (1 Year), requiring controlled storage conditions. All other substitutes maintain MSL 1 (Unlimited) rating.