SN74AHC240DBR Equivalent & Substitute Parts

Part Overview

The SN74AHC240DBR is a Buffer, Inverting logic IC manufactured by Texas Instruments, featuring 2 elements with 4 bits per element and 3-state output capability. This component operates across a supply voltage range of 2V to 5.5V and is housed in a 20-SSOP package with a width of 5.30mm. The device is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

SN74AHC240DBR

Texas InstrumentsIn Stock: 1122SN74AHC240DBR Datasheet

Current PartRFQ

74VHC240MTCX

onsemiIn Stock: 198474VHC240MTCX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74AHC240DBR is determined by strict equivalence across the following critical parameters:

• Logic Type: Buffer, Inverting (2 elements, 4 bits per element)
• Output Type: 3-State
• Output Current Capability: 8mA high and low
• Supply Voltage Range: 2V ~ 5.5V minimum compatibility
• Operating Temperature Range: -40°C ~ 85°C minimum coverage
• Mounting Type: Surface Mount
• RoHS3 Compliance and MSL Level 1 rating

The 74VHC240MTCX meets all substitution criteria. While package geometry differs (20-TSSOP at 4.40mm width versus 20-SSOP at 5.30mm width), both packages are surface-mount 20-pin configurations with identical pin assignments and electrical specifications, permitting direct functional substitution with PCB layout adjustment.

Parameter Comparison

Engineering Selection Recommendations

The 74VHC240MTCX is a direct functional equivalent to the SN74AHC240DBR. Both devices maintain identical electrical specifications, logic functionality, and compliance certifications (ROHS3, MSL Level 1, REACH Unaffected). The primary distinction is product status: the SN74AHC240DBR is obsolete while the 74VHC240MTCX remains in active production with confirmed inventory availability (1892 pcs).

Package geometry differs between the two devices (SSOP versus TSSOP), requiring PCB layout modification. Both packages are 20-pin surface-mount configurations with equivalent pin assignments, ensuring electrical compatibility without schematic changes. The narrower TSSOP package (4.40mm) may provide space optimization benefits in constrained layouts.

Selection of the 74VHC240MTCX is supported by active manufacturing status, regulatory compliance alignment, and sustained supply chain availability.

Frequently Asked Questions (FAQ)

Q: Can the 74VHC240MTCX directly replace the SN74AHC240DBR without circuit modifications?

A: Electrical and functional replacement is direct. Pin assignments and signal behavior are identical. PCB layout modification is required due to package geometry differences (SSOP versus TSSOP), but no schematic changes are necessary.

Q: What is the primary reason for substitution?

A: The SN74AHC240DBR is classified as obsolete. The 74VHC240MTCX provides equivalent functionality with active production status and confirmed supply availability.

Q: Are there compliance or regulatory differences between these parts?

A: Both devices are ROHS3 compliant, carry MSL Level 1 rating, and are REACH unaffected. Compliance profiles are identical.

Q: How do the package dimensions affect PCB design?

A: The SN74AHC240DBR uses 20-SSOP packaging (5.30mm width) while the 74VHC240MTCX uses 20-TSSOP packaging (4.40mm width). Pin pitch and assignments remain consistent. PCB footprint adjustment is required; the TSSOP variant occupies less board space.

Q: What are the output current specifications for both devices?

A: Both the SN74AHC240DBR and 74VHC240MTCX provide 8mA output current capability for both high and low states, ensuring equivalent drive capability in 3-state buffer applications.

Q: Is the supply voltage range identical?

A: Yes. Both devices operate across 2V to 5.5V supply voltage range with identical operating temperature specifications of -40°C to 85°C (TA).