SN74LS240NE4 Equivalent & Substitute Parts

Part Overview

The SN74LS240NE4 is an 8-channel inverting buffer logic integrated circuit manufactured by Texas Instruments. This component functions as a 2-element, 4-bit-per-element buffer with 3-state output capability, designed for digital logic applications requiring signal inversion and buffering in 5V TTL systems. The device operates within a supply voltage range of 4.75V to 5.25V and is housed in a 20-pin DIP package suitable for through-hole mounting.

The SN74LS240NE4 maintains Active product status with 654 pieces currently in stock. Identifying equivalent and substitute parts is necessary to ensure design flexibility, manage supply chain continuity, and accommodate alternative sourcing when the primary part becomes unavailable or when design requirements necessitate component alternatives with identical electrical and mechanical specifications.

Substiute Parts

SN74LS240NE4

Texas InstrumentsIn Stock: 702SN74LS240NE4 Datasheet

Current PartRFQ

SN74LS240N

onsemiIn Stock: 2008SN74LS240N Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the SN74LS240NE4 is determined by strict equivalence across the following critical parameters:

Electrical Equivalence Criteria:

• Logic type must be Buffer, Inverting
• Number of elements must equal 2
• Number of bits per element must equal 4
• Output type must be 3-State
• Output current specifications must match: 15mA (high), 24mA (low)
• Supply voltage range must be 4.75V ~ 5.25V
• Operating temperature range must be 0°C ~ 70°C

Mechanical Equivalence Criteria:

• Package type must be 20-DIP (0.300", 7.62mm)
• Mounting type must be Through Hole
• Series designation must be 74LS

The SN74LS240N from onsemi meets all electrical and mechanical equivalence criteria and is classified as a parametric equivalent. Substitution is valid based on identical functional specifications and package compatibility.

Parameter Comparison

Engineering Selection Recommendations

SN74LS240NE4 (Primary Selection): The SN74LS240NE4 from Texas Instruments is the recommended primary selection. This part maintains Active product status, ensuring long-term availability and continued manufacturing support. The component is ROHS3 compliant, meeting current environmental and regulatory requirements for new designs and applications subject to RoHS directives. Current inventory of 654 pieces supports immediate procurement needs.

SN74LS240N (Substitute Selection): The SN74LS240N from onsemi is a parametric equivalent suitable for substitution in applications where the primary part is unavailable. This part carries Obsolete product status, indicating discontinued manufacturing and limited future availability. The component is RoHS non-compliant, which restricts its use in new designs or applications requiring RoHS compliance. The SN74LS240N is appropriate for legacy system maintenance, repair, or retrofit applications where RoHS compliance is not a requirement. Current inventory of 1900 pieces provides temporary supply availability.

Selection between these parts must account for product lifecycle status and regulatory compliance requirements specific to the application and end-use market.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS240N be used as a direct replacement for the SN74LS240NE4?

A: The SN74LS240N is electrically and mechanically equivalent to the SN74LS240NE4. Both parts share identical logic type, element configuration, output specifications, supply voltage range, operating temperature range, and 20-DIP package dimensions. Direct pin-for-pin substitution is valid from an electrical standpoint. However, product status and RoHS compliance differences must be evaluated against application requirements before substitution.

Q: What are the key differences between these two parts?

A: The primary differences are product status and regulatory compliance. The SN74LS240NE4 is Active and ROHS3 compliant, while the SN74LS240N is Obsolete and RoHS non-compliant. Electrical and mechanical specifications are identical. Manufacturer differences (Texas Instruments versus onsemi) reflect different production sources for the same 74LS logic family design.

Q: Is the 20-DIP package compatible with modern PCB designs?

A: The 20-DIP (0.300", 7.62mm) package is a through-hole component designed for traditional PCB assembly methods. Both the SN74LS240NE4 and SN74LS240N use identical package dimensions and mounting specifications. Compatibility depends on PCB design supporting through-hole mounting technology. Modern designs may require adapter solutions or alternative surface-mount logic components if through-hole mounting is not supported.

Q: Can these parts be used interchangeably in new product designs?

A: The SN74LS240NE4 is the appropriate selection for new product designs due to its Active status and ROHS3 compliance. The SN74LS240N, being Obsolete and RoHS non-compliant, is not suitable for new designs subject to RoHS requirements or designs requiring long-term component availability and manufacturing support.

Q: What supply voltage tolerance must be maintained for proper operation?

A: Both parts require supply voltage within the range of 4.75V to 5.25V. This 5V nominal supply specification is standard for 74LS TTL logic family components. Supply voltage must remain within this tolerance band during operation to ensure specified output current and logic level performance.

Q: Are there any differences in output current capabilities?

A: No. Both the SN74LS240NE4 and SN74LS240N provide identical output current specifications: 15mA maximum output high current and 24mA maximum output low current. These specifications determine the maximum fan-out and load-driving capability for each output channel.