74F20SCX NAND Gate IC Equivalent & Substitute Parts

Part Overview

The 74F20SCX is a dual 4-input NAND gate logic IC manufactured by onsemi in 14-SOIC surface mount packaging. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The 74F20 series provides standard TTL-compatible logic functionality suitable for digital circuit applications requiring NAND gate operations.

Substiute Parts

74F20SCX

onsemiIn Stock: 369374F20SCX Datasheet

Current PartRFQ

SN74F20D

Texas InstrumentsIn Stock: 1648SN74F20D Datasheet

DirectRFQ

SN74F20DR

Texas InstrumentsIn Stock: 3975SN74F20DR Datasheet

DirectRFQ

SN74F20NSR

Texas InstrumentsIn Stock: 3273SN74F20NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74F20SCX is determined by the following criteria:

Direct Substitutes maintain identical electrical specifications and package dimensions:

• Logic type: NAND Gate
• Circuit count: 2 channels
• Input count: 4 per channel
• Supply voltage: 4.5V ~ 5.5V
• Output current ratings: 1mA / 20mA
• Input logic levels: 0.8V (low) / 2V (high)
• Operating temperature: 0°C ~ 70°C
• Package footprint: 14-SOIC (0.154", 3.90mm width)

Similar Substitutes meet all electrical requirements but differ in package dimensions:

• All electrical parameters identical to direct substitutes
• Package variant: 14-SO (0.209", 5.30mm width) instead of standard 14-SOIC
• Requires PCB layout adjustment due to increased body width

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: SN74F20DR

The SN74F20DR is the recommended substitute for the 74F20SCX. This Texas Instruments part maintains identical package dimensions (14-SOIC, 0.154" width), meets all electrical specifications, and carries Active product status with ROHS3 compliance. Tape & Reel packaging supports automated assembly processes. Propagation delay of 6ns at 5V, 50pF represents a 1ns increase from the original specification, which remains within acceptable tolerance for standard TTL logic applications.

Secondary Selection: SN74F20D

The SN74F20D provides direct electrical and package compatibility with identical 14-SOIC dimensions. This part carries Last Time Buy status, indicating limited future availability. Tube packaging is suitable for manual assembly or lower-volume production. Select this option only when SN74F20DR is unavailable.

Alternative Selection: SN74F20NSR

The SN74F20NSR maintains all electrical specifications and Active product status but uses 14-SO packaging with increased body width (0.209" versus 0.154"). This part requires PCB layout modification to accommodate the wider package footprint. Select only when 14-SOIC variants are unavailable and PCB redesign is feasible.

Frequently Asked Questions (FAQ)

Q: Can SN74F20DR replace 74F20SCX directly on existing PCBs?

A: Yes. The SN74F20DR uses identical 14-SOIC packaging with 0.154" body width, matching the original 74F20SCX footprint. No PCB modifications are required.

Q: What is the significance of the 1ns propagation delay difference between 74F20SCX and substitute parts?

A: The 74F20SCX specifies 5ns maximum propagation delay while SN74F20D and SN74F20DR specify 6ns. This 1ns difference is typical among 74F-series logic variants and does not affect functional compatibility in standard TTL applications. Verify timing margins in critical path analysis if required.

Q: Why does SN74F20NSR have different package dimensions?

A: The SN74F20NSR uses 14-SO packaging (0.209" width) instead of 14-SOIC (0.154" width). Both are 14-pin surface mount packages with identical pin spacing and electrical function. The wider body requires PCB layout adjustment and is not a direct footprint replacement.

Q: Is ROHS3 compliance required for my application?

A: The SN74F20D, SN74F20DR, and SN74F20NSR all carry ROHS3 Compliant certification. The original 74F20SCX does not specify RoHS status. Verify RoHS requirements with your design specifications and regulatory requirements.

Q: What packaging format should I select for production?

A: SN74F20DR in Tape & Reel (TR) format is optimized for automated assembly. SN74F20D in Tube format supports manual assembly or lower-volume production. Select based on your manufacturing process and volume requirements.

Q: Are all substitute parts pin-compatible with 74F20SCX?

A: Yes. All listed substitutes maintain identical pin configuration, voltage levels, and logic function. Pin-to-pin compatibility is guaranteed across all direct and similar substitutes.