74F240SCX Equivalent & Substitute Parts

Part Overview

The 74F240SCX is an inverting buffer logic integrated circuit manufactured by onsemi, designed for 5.5V operation with 2 elements and 4 bits per element, featuring 3-state output capability in a 20-SOIC package. The part is currently obsolete, making equivalent and substitute components necessary for ongoing system support and new designs requiring this functional specification.

Substiute Parts

74F240SCX

onsemiIn Stock: 1626174F240SCX Datasheet

Current PartRFQ

SN74F240DW

Texas InstrumentsIn Stock: 1521SN74F240DW Datasheet

DirectRFQ

SN74F240DWR

Texas InstrumentsIn Stock: 2153SN74F240DWR Datasheet

DirectRFQ

SN74F240NSR

Texas InstrumentsIn Stock: 3274SN74F240NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74F240SCX is determined by the following critical parameters: logic type (Buffer, Inverting), functional configuration (2 elements, 4 bits per element), output type (3-State), supply voltage range (4.5V ~ 5.5V), operating temperature range (0°C ~ 70°C), and package compatibility (20-SOIC surface mount).

Substitute parts are classified into two categories:

Direct Substitutes (Identical Package): Parts maintaining the 20-SOIC (0.295", 7.50mm Width) package specification, enabling direct board-level replacement without layout modification.

Similar Substitutes (Package Variant): Parts with equivalent electrical specifications but different package dimensions (20-SO with 0.209", 5.30mm Width), requiring PCB layout adjustment for implementation.

Parameter Comparison

Engineering Selection Recommendations

SN74F240DWR (Texas Instruments) is the primary substitute for the 74F240SCX. This part maintains identical package dimensions (20-SOIC, 0.295", 7.50mm Width), electrical specifications, and operating parameters. The SN74F240DWR carries Active product status with ROHS3 compliance, ensuring long-term availability and regulatory alignment for new designs and production continuity.

SN74F240DW (Texas Instruments) provides equivalent electrical and package compatibility with the 74F240SCX. This part is classified as Last Time Buy, indicating limited future availability. Selection of this part should be reserved for applications requiring specific packaging formats (Tube) or where inventory constraints necessitate alternative sourcing.

SN74F240NSR (Texas Instruments) offers electrical equivalence with a package variant (20-SO, 0.209", 5.30mm Width). This narrower package requires PCB layout modification and is suitable only for applications where board space constraints justify redesign effort. The part maintains Active product status and ROHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can SN74F240DWR directly replace 74F240SCX without PCB modification?

A: Yes. The SN74F240DWR maintains identical package dimensions (20-SOIC, 0.295", 7.50mm Width) and electrical specifications, enabling direct board-level substitution without layout changes.

Q: What is the difference in output current between 74F240SCX and the Texas Instruments substitutes?

A: The 74F240SCX specifies 3mA output high current, while SN74F240DW, SN74F240DWR, and SN74F240NSR specify 15mA output high current. All parts maintain 64mA output low current. The higher output high current in Texas Instruments parts provides improved drive capability.

Q: Is SN74F240NSR compatible with existing PCB designs for 74F240SCX?

A: No. The SN74F240NSR uses a narrower 20-SO package (0.209", 5.30mm Width) compared to the 74F240SCX 20-SOIC package (0.295", 7.50mm Width). PCB footprint and layout modification is required for implementation.

Q: What is the product status difference between the substitute parts?

A: SN74F240DWR is Active, ensuring ongoing availability. SN74F240DW is Last Time Buy, indicating limited future production. SN74F240NSR is Active. For new designs, SN74F240DWR is the recommended selection based on product lifecycle status.

Q: Are all substitute parts RoHS compliant?

A: Yes. SN74F240DW, SN74F240DWR, and SN74F240NSR are all ROHS3 compliant. The original 74F240SCX RoHS status is not specified in available documentation.