SN74AC240DW Equivalent & Substitute Parts

Part Overview

The SN74AC240DW is an inverting buffer logic IC manufactured by Texas Instruments, designed for 2-element, 4-bit-per-element buffering applications with 3-state output capability. This device operates across a 2V to 6V supply voltage range and is housed in a 20-SOIC surface mount package. The SN74AC240DW is currently discontinued at DiGi Electronics, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

SN74AC240DW

Texas InstrumentsIn Stock: 1829SN74AC240DW Datasheet

Current PartRFQ

SN74AC240DWR

Texas InstrumentsIn Stock: 2789SN74AC240DWR Datasheet

DirectRFQ

MC74AC240DWR2G

onsemiIn Stock: 1040MC74AC240DWR2G Datasheet

MFR RecommendedRFQ

74AC240SC

Fairchild SemiconductorIn Stock: 310474AC240SC Datasheet

Parametric EquivalentRFQ

MC74AC240DWG

onsemiIn Stock: 1190MC74AC240DWG Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74AC240DW are qualified based on strict electrical and mechanical parameter matching. The following criteria determine substitution eligibility:

• Logic Type: Buffer, Inverting (identical function)
• Number of Elements: 2 (identical configuration)
• Number of Bits per Element: 4 (identical configuration)
• Output Type: 3-State (identical output behavior)
• Current - Output High, Low: 24mA, 24mA (identical drive capability)
• Voltage - Supply: 2V ~ 6V (identical supply range)
• Operating Temperature: -40°C ~ 85°C (TA) (identical thermal range)
• Package / Case: 20-SOIC (0.295", 7.50mm Width) (identical footprint and pinout)
• Mounting Type: Surface Mount (identical assembly method)

All substitute parts listed below meet these core parameters and are therefore electrically and mechanically interchangeable with the SN74AC240DW.

Parameter Comparison

Engineering Selection Recommendations

SN74AC240DWR (Texas Instruments, Active): This direct manufacturer equivalent maintains identical electrical specifications and RoHS3 compliance with MSL 1 rating. The primary difference is packaging format (Tape & Reel versus Tube). This part is recommended for new designs and ongoing procurement due to active product status.

MC74AC240DWR2G (onsemi, Active): This manufacturer-recommended equivalent provides full electrical compatibility and ROHS3 compliance. The MSL rating is 3 (168 Hours) compared to MSL 1 for the original part. This part is suitable for applications where moisture sensitivity handling procedures are implemented during assembly.

74AC240SC (Fairchild Semiconductor, Active): This parametric equivalent meets all electrical and mechanical requirements. Packaging format is Bulk. RoHS and MSL specifications are not provided in the available data. Verification of compliance requirements is necessary before selection.

MC74AC240DWG (onsemi, Obsolete): This part meets all electrical and mechanical parameters but carries an Obsolete product status. Selection should be limited to legacy system support or where existing inventory is available.

Frequently Asked Questions (FAQ)

Q: Can SN74AC240DWR be used as a direct replacement for SN74AC240DW?

A: Yes. Both parts are manufactured by Texas Instruments and share identical electrical specifications, operating temperature range, supply voltage, output current, and 20-SOIC package footprint. The only difference is packaging format (Tape & Reel versus Tube), which does not affect circuit functionality.

Q: What is the significance of the MSL (Moisture Sensitivity Level) difference between SN74AC240DW (MSL 1) and MC74AC240DWR2G (MSL 3)?

A: MSL 1 indicates unlimited shelf life under standard conditions. MSL 3 requires controlled moisture exposure during storage and handling, with a maximum floor life of 168 hours after bag opening. Selection depends on your assembly process capabilities and storage environment.

Q: Are all substitute parts ROHS3 compliant?

A: SN74AC240DWR, MC74AC240DWR2G, and MC74AC240DWG are confirmed ROHS3 compliant. The 74AC240SC does not have RoHS status specified in available documentation. Compliance verification is recommended before procurement.

Q: What is the difference between Tube, Tape & Reel, and Bulk packaging?

A: Tube packaging contains individual components in a plastic tube, suitable for manual handling and small-quantity orders. Tape & Reel packaging is automated assembly-ready format with components on carrier tape. Bulk packaging is loose components without specific packaging format. All three formats contain electrically identical parts; selection depends on assembly process requirements.

Q: Is the 74AC240SC from Fairchild Semiconductor a suitable substitute?

A: The 74AC240SC meets all electrical and mechanical parameters. However, RoHS and MSL specifications are not provided. Compliance verification with your regulatory and assembly requirements is necessary before selection.

Q: Why is MC74AC240DWG marked as Obsolete?

A: Obsolete status indicates the manufacturer has discontinued production. While existing inventory may be available, this part should not be selected for new designs. Use SN74AC240DWR or MC74AC240DWR2G for ongoing projects.