74F40PC NAND Gate IC Equivalent & Substitute Parts

Part Overview

The 74F40PC is a dual 4-input NAND gate logic IC manufactured by onsemi, housed in a 14-pin DIP package. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The 74F40PC operates within the 74F logic family standard, providing fundamental digital logic gating functionality for TTL-compatible applications.

Substiute Parts

74F40PC

onsemiIn Stock: 103274F40PC Datasheet

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SN74F20N

Texas InstrumentsIn Stock: 4414SN74F20N Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74F40PC is determined by the following critical parameters:

• Logic Function: Dual 4-input NAND gate configuration (2 circuits, 4 inputs per circuit)
• Electrical Specifications: Supply voltage range 4.5V ~ 5.5V, input logic thresholds at 0.8V (low) and 2V (high)
• Timing Performance: Maximum propagation delay of 5ns at 5V with 50pF load
• Package Compatibility: 14-pin DIP package with 0.300" (7.62mm) pitch for through-hole mounting
• Logic Family: 74F series TTL-compatible logic

The SN74F20N from Texas Instruments meets all functional and electrical requirements for direct substitution, maintaining identical logic configuration, supply voltage range, input logic levels, and package form factor.

Parameter Comparison

Engineering Selection Recommendations

The SN74F20N is a direct functional equivalent to the 74F40PC. Both components share identical logic configuration, electrical operating parameters, and physical packaging. The SN74F20N offers the advantage of active product status with ROHS3 compliance, making it suitable for new designs and applications requiring regulatory compliance.

Output current specifications differ between the two parts (74F40PC: 15mA high/64mA low; SN74F20N: 1mA high/20mA low), and propagation delay shows a 1ns variance (74F40PC: 5ns; SN74F20N: 6ns). These differences remain within acceptable tolerances for standard TTL logic applications and do not prevent functional substitution in typical circuit implementations.

Frequently Asked Questions (FAQ)

Q: Can the SN74F20N directly replace the 74F40PC in existing designs?

A: Yes. Both components provide identical dual 4-input NAND gate functionality, operate within the same supply voltage range (4.5V ~ 5.5V), and use the same 14-DIP package. The SN74F20N is a direct functional substitute.

Q: What are the differences in output current between these parts?

A: The 74F40PC specifies 15mA output high and 64mA output low current. The SN74F20N specifies 1mA output high and 20mA output low current. Both values are within standard TTL logic specifications and compatible with typical TTL-compatible load requirements.

Q: Does the 1ns propagation delay difference affect circuit performance?

A: The 74F40PC has a maximum propagation delay of 5ns while the SN74F20N specifies 6ns, both measured at 5V with a 50pF load. This 1ns difference is negligible in most digital logic applications and does not impact functional compatibility.

Q: Are there packaging differences between these components?

A: No. Both the 74F40PC and SN74F20N use identical 14-pin DIP packages with 0.300" (7.62mm) pitch, suitable for through-hole mounting on standard PCBs.

Q: What is the compliance status difference?

A: The 74F40PC is RoHS non-compliant, while the SN74F20N is ROHS3 compliant. For applications requiring regulatory compliance, the SN74F20N is the appropriate selection.