74AC240PC Equivalent & Substitute Parts

Part Overview

The 74AC240PC is a Buffer, Inverting logic integrated circuit manufactured by onsemi, featuring 2 elements with 4 bits per element and 3-state output capability. This device is designed for signal buffering and inversion applications in digital logic systems operating at supply voltages between 2V and 6V. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing procurement and system maintenance.

Substiute Parts

74AC240PC

onsemiIn Stock: 330874AC240PC Datasheet

Current PartRFQ

SN74AC240N

Texas InstrumentsIn Stock: 2622SN74AC240N Datasheet

DirectRFQ

CD74AC240E

Harris CorporationIn Stock: 2264CD74AC240E Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 74AC240PC are identified based on strict electrical and mechanical compatibility criteria. The following parameters determine valid substitution:

• Logic Type: Buffer, Inverting (must match exactly)
• Number of Elements: 2 (must match exactly)
• Number of Bits per Element: 4 (must match exactly)
• Output Type: 3-State (must match exactly)
• Current - Output High, Low: 24mA, 24mA (must match exactly)
• Package / Case: 20-DIP (0.300", 7.62mm) (must match exactly)
• Mounting Type: Through Hole (must match exactly)
• Operating Temperature Range: -40°C ~ 85°C (TA) (must match exactly)

Substitute parts are categorized as follows:

Direct Substitutes: Parts that meet all electrical and mechanical parameters with identical or compatible supply voltage ranges and active product status.

Similar Substitutes: Parts that meet all core electrical and mechanical parameters but may have different supply voltage ranges or obsolete status.

Parameter Comparison

Engineering Selection Recommendations

SN74AC240N (Texas Instruments) is the primary substitute for the 74AC240PC. This part maintains identical electrical specifications and package configuration while offering active product status and ROHS3 compliance. The supply voltage range (2V ~ 6V) is fully compatible with the original specification.

CD74AC240E (Harris Corporation) is a secondary substitute option. While it meets all core electrical and mechanical parameters, the supply voltage range (1.5V ~ 5.5V) is narrower at the upper limit, and the part carries obsolete status with RoHS non-compliance. This part is suitable only when the lower minimum supply voltage (1.5V) is required and the upper voltage limit of 5.5V is acceptable for the application.

For new designs and ongoing procurement, SN74AC240N is the recommended choice due to active availability and compliance certifications.

Frequently Asked Questions (FAQ)

Q: Can SN74AC240N directly replace 74AC240PC in existing designs?

A: Yes. SN74AC240N meets all electrical and mechanical specifications of the 74AC240PC, including logic type, element count, bit configuration, output type, current ratings, supply voltage range, operating temperature, and 20-DIP package format. Direct substitution is electrically and mechanically compatible.

Q: What is the difference between the supply voltage ranges of 74AC240PC and CD74AC240E?

A: The 74AC240PC operates at 2V ~ 6V, while CD74AC240E operates at 1.5V ~ 5.5V. The CD74AC240E has a lower minimum voltage but a lower maximum voltage. Substitution is valid only if the application operates within the 1.5V ~ 5.5V range.

Q: Why is SN74AC240N preferred over CD74AC240E?

A: SN74AC240N is preferred because it maintains the full 2V ~ 6V supply voltage range of the original 74AC240PC, carries active product status ensuring continued availability, and meets ROHS3 compliance standards. CD74AC240E is obsolete and RoHS non-compliant.

Q: Are all substitute parts available in the same packaging format?

A: Yes. All substitute parts listed are available in 20-DIP (0.300", 7.62mm) through-hole packaging, identical to the 74AC240PC. No PCB layout modifications are required for substitution.

Q: What certifications should I verify for compliance requirements?

A: SN74AC240N is ROHS3 compliant and suitable for applications requiring RoHS compliance. The 74AC240PC and CD74AC240E do not carry RoHS compliance certifications. Verify compliance requirements for your specific application before selection.