SN74HC240ANS Equivalent & Substitute Parts

Part Overview

The SN74HC240ANS is an inverting buffer logic integrated circuit manufactured by Texas Instruments, designed for digital signal buffering and inversion applications. This device features 2 elements with 4 bits per element and 3-state output capability in a 20-SOIC surface mount package. The SN74HC240ANS is classified as Last Time Buy, indicating discontinued production status. Identifying equivalent substitute parts is necessary to ensure continued design support, maintain supply chain continuity, and enable procurement of functionally compatible alternatives for new production runs or design revisions.

Substiute Parts

SN74HC240ANS

Texas InstrumentsIn Stock: 987SN74HC240ANS Datasheet

Current PartRFQ

SN74HC240ANSR

Texas InstrumentsIn Stock: 2965SN74HC240ANSR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74HC240ANS is determined by strict equivalence across the following critical parameters:

Functional Parameters:

• Logic Type: Buffer, Inverting (identical function required)
• Number of Elements: 2 (pin-for-pin compatibility)
• Number of Bits per Element: 4 (functional capacity)
• Output Type: 3-State (output control capability)

Electrical Parameters:

• Current - Output High, Low: 7.8mA, 7.8mA (drive capability)
• Voltage - Supply: 2V ~ 6V (operating range)
• Operating Temperature: -40°C ~ 85°C (TA) (thermal range)

Physical & Compliance Parameters:

• Package / Case: 20-SOIC (0.209", 5.30mm Width) (PCB footprint compatibility)
• Mounting Type: Surface Mount (assembly process compatibility)
• RoHS Status: ROHS3 Compliant (environmental compliance)
• Moisture Sensitivity Level (MSL): 1 (Unlimited) (handling requirements)

The SN74HC240ANSR qualifies as a direct substitute based on complete parameter alignment across all functional, electrical, physical, and compliance criteria.

Parameter Comparison

Engineering Selection Recommendations

The SN74HC240ANSR is the qualified substitute for the SN74HC240ANS based on complete electrical and mechanical parameter equivalence. The primary distinction between these parts is product status and packaging format:

SN74HC240ANS is designated Last Time Buy, indicating end-of-life status with limited future availability. This part is suitable only for existing designs requiring component replacement or for applications where existing inventory is available.

SN74HC240ANSR maintains Active product status with continuous manufacturing support from Texas Instruments. This part is supplied in Tape & Reel (TR) packaging, which is standard for high-volume production environments. The Active status ensures long-term supply chain reliability and design continuity.

Both parts maintain identical ROHS3 compliance and MSL Level 1 (Unlimited) moisture sensitivity classification, confirming equivalent environmental and handling requirements. The 20-SOIC package footprint is identical, enabling direct PCB layout compatibility without design modification.

For new designs or production revisions, the SN74HC240ANSR is the appropriate selection due to Active product status and standard production packaging. For existing designs currently using SN74HC240ANS, the SN74HC240ANSR provides direct functional and physical substitution.

Frequently Asked Questions (FAQ)

Q: Can SN74HC240ANSR be used as a direct replacement for SN74HC240ANS in existing designs?

A: Yes. Both parts are electrically and mechanically equivalent. The 20-SOIC package footprint, pin configuration, functional behavior, and electrical specifications are identical. No design modification is required for substitution.

Q: What is the difference between SN74HC240ANS and SN74HC240ANSR?

A: The primary differences are product status and packaging format. SN74HC240ANS is Last Time Buy (discontinued), supplied in tube packaging. SN74HC240ANSR is Active (current production), supplied in Tape & Reel (TR) format. All electrical and mechanical parameters are identical.

Q: Why is SN74HC240ANS classified as Last Time Buy?

A: Last Time Buy designation indicates that Texas Instruments has discontinued production of this part number. Existing inventory may be available through authorized distributors, but future availability is not guaranteed. The SN74HC240ANSR provides continued access to this functionality through an Active product number.

Q: Are there any compliance or certification differences between these parts?

A: No. Both parts maintain identical ROHS3 compliance status and MSL Level 1 (Unlimited) moisture sensitivity classification. Environmental and handling requirements are equivalent.

Q: What is the significance of Tape & Reel (TR) packaging for SN74HC240ANSR?

A: Tape & Reel packaging is the standard format for automated surface mount assembly processes. This packaging enables high-speed pick-and-place machine compatibility and is required for volume production environments. Tube packaging (SN74HC240ANS) is typically used for lower-volume or manual assembly applications.

Q: Can the 20-SOIC package be used interchangeably on the same PCB?

A: Yes. Both parts use the identical 20-SOIC (0.209", 5.30mm Width) package. The PCB footprint, solder pad layout, and component placement are identical. No PCB redesign is necessary.

Q: What output current capability should be considered for circuit design?

A: Both parts provide 7.8mA output current capability for both high and low logic states. Circuit designs must account for this drive capability when interfacing with downstream logic or load devices.

Q: What supply voltage range is supported?

A: Both parts operate across a 2V to 6V supply voltage range. This wide operating range supports both 3.3V and 5V logic system designs without modification.