74F74SCX Equivalent & Substitute Parts

Part Overview

The 74F74SCX is a dual D-type flip-flop logic integrated circuit manufactured by onsemi, housed in a 14-SOIC surface mount package. This component is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The 74F74 series provides two independent D-type flip-flops with complementary outputs, set/preset and reset functions, and positive edge triggering suitable for digital logic applications requiring state storage and synchronization.

Substiute Parts

74F74SCX

onsemiIn Stock: 3302574F74SCX Datasheet

Current PartRFQ

SN74F74D

Texas InstrumentsIn Stock: 5804SN74F74D Datasheet

DirectRFQ

SN74F74DR

Texas InstrumentsIn Stock: 8068SN74F74DR Datasheet

DirectRFQ

SN74F74NSR

Texas InstrumentsIn Stock: 4077SN74F74NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the 74F74SCX is determined by strict adherence to the following electrical and mechanical parameters:

Critical Substitution Parameters:

• Dual D-type flip-flop architecture with 2 elements, 1 bit per element
• Complementary output configuration
• Positive edge trigger functionality
• Set/Preset and Reset function capability
• Supply voltage range: 4.5V ~ 5.5V
• Operating temperature: 0°C ~ 70°C
• Surface mount packaging in 14-pin SOIC form factor

Substitution Categories:

Direct Substitutes (Electrical and Mechanical Equivalence):

• SN74F74D (Texas Instruments) – 14-SOIC (0.154", 3.90mm Width)
• SN74F74DR (Texas Instruments) – 14-SOIC (0.154", 3.90mm Width)

Similar Substitute (Package Variant):

• SN74F74NSR (Texas Instruments) – 14-SOIC (0.209", 5.30mm Width) – Wider package footprint

All substitute parts maintain the core 74F logic family specifications and functional equivalence required for direct replacement in applications designed for the 74F74SCX.

Parameter Comparison

Engineering Selection Recommendations

Primary Recommendation: SN74F74DR (Texas Instruments)

The SN74F74DR is the preferred substitute for the obsolete 74F74SCX. This part maintains identical electrical specifications and mechanical packaging (14-SOIC, 0.154" width), ensuring direct PCB compatibility without layout modifications. The SN74F74DR carries Active product status with ROHS3 compliance, providing long-term availability and regulatory alignment. Performance characteristics exceed the original part, with faster propagation delay (5.8 ns vs. 6.8 ns) and higher clock frequency (145 MHz vs. 125 MHz), delivering improved timing margins in existing designs.

Secondary Recommendation: SN74F74D (Texas Instruments)

The SN74F74D offers identical electrical and mechanical specifications to the 74F74SCX with the same package footprint. This part is classified as Last Time Buy, indicating limited future availability. Selection of this part should be reserved for applications where inventory acquisition is immediately feasible or where design validation has been completed with this specific part number.

Alternative Consideration: SN74F74NSR (Texas Instruments)

The SN74F74NSR provides functional equivalence with identical electrical performance but features a wider 14-SOIC package (0.209" vs. 0.154" width). This part is suitable only for designs where PCB layout can accommodate the larger footprint or where existing designs already utilize this package variant. The SN74F74NSR carries Active status and ROHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can the SN74F74DR be used as a direct replacement for the 74F74SCX without PCB modifications?

A: Yes. The SN74F74DR maintains identical package dimensions (14-SOIC, 0.154" width), pin configuration, and electrical specifications. No PCB layout changes are required for direct substitution.

Q: What is the difference between the SN74F74D and SN74F74DR?

A: Both parts are electrically and mechanically identical. The primary difference is packaging format: SN74F74D is supplied in Tube packaging, while SN74F74DR is supplied in Cut Tape and Digi-Reel format. Product status differs, with SN74F74D classified as Last Time Buy and SN74F74DR as Active.

Q: Why is the SN74F74NSR listed as a similar substitute rather than a direct substitute?

A: The SN74F74NSR uses a wider 14-SOIC package (0.209" vs. 0.154" width), resulting in a different PCB footprint. While electrically equivalent, this package variant requires PCB layout verification to confirm compatibility with existing designs. Propagation delay is also slightly higher at 8 ns compared to 5.8 ns for the direct substitutes.

Q: Are all substitute parts RoHS compliant?

A: Yes. All Texas Instruments substitute parts (SN74F74D, SN74F74DR, SN74F74NSR) are ROHS3 compliant. The original 74F74SCX RoHS status was not specified in available documentation.

Q: What is the availability status of each substitute part?

A: SN74F74DR is the recommended choice with Active product status, ensuring long-term availability. SN74F74D is classified as Last Time Buy with limited future supply. SN74F74NSR is Active and available. The original 74F74SCX is Obsolete.

Q: Do the substitute parts have improved performance compared to the 74F74SCX?

A: Yes. The SN74F74D and SN74F74DR both feature faster maximum propagation delay (5.8 ns vs. 6.8 ns) and higher clock frequency (145 MHz vs. 125 MHz), providing improved timing performance in applications requiring these specifications.

Q: Can multiple substitute parts be used interchangeably within the same design?

A: SN74F74D and SN74F74DR are fully interchangeable due to identical electrical and mechanical specifications. The SN74F74NSR requires PCB layout verification due to its wider package footprint and should not be mixed with the narrower variants on the same board without design review.