74AC74SC Equivalent & Substitute Parts

Part Overview

The 74AC74SC is a dual D-type flip-flop logic integrated circuit manufactured by onsemi, housed in a 14-SOIC package. This component functions as a Set/Preset and Reset element with complementary outputs, operating at a maximum clock frequency of 160 MHz. The part is currently listed as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement.

Substiute Parts

74AC74SC

onsemiIn Stock: 160874AC74SC Datasheet

Current PartRFQ

MC74AC74DR2G

onsemiIn Stock: 2964MC74AC74DR2G Datasheet

DirectRFQ

MC74AC74DG

onsemiIn Stock: 2540MC74AC74DG Datasheet

Parametric EquivalentRFQ

SN74AC74D

Texas InstrumentsIn Stock: 1999SN74AC74D Datasheet

DirectRFQ

SN74AC74DR

Texas InstrumentsIn Stock: 5241SN74AC74DR Datasheet

DirectRFQ

SN74AC74MDREP

Texas InstrumentsIn Stock: 3394SN74AC74MDREP Datasheet

UpgradeRFQ

74AC11074D

Texas InstrumentsIn Stock: 98174AC11074D Datasheet

SimilarRFQ

74AC11074DR

Texas InstrumentsIn Stock: 149474AC11074DR Datasheet

SimilarRFQ

CD74AC74M96

Texas InstrumentsIn Stock: 6333CD74AC74M96 Datasheet

SimilarRFQ

SN74AC74NSR

Texas InstrumentsIn Stock: 3440SN74AC74NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74AC74SC is determined by the following critical parameters:

Core Functional Parameters:

• Type: D-Type Flip-Flop with 2 Elements, 1 Bit per Element
• Output Type: Complementary
• Trigger Type: Positive Edge
• Function: Set/Preset and Reset capability

Electrical Performance Parameters:

• Clock Frequency: Minimum 160 MHz
• Max Propagation Delay @ 5V, 50pF: Maximum 10 ns
• Supply Voltage Range: Must encompass 2V to 6V
• Output Current: 24 mA (High and Low)

Physical Parameters:

• Package: 14-SOIC (0.154", 3.90mm Width)
• Mounting Type: Surface Mount

Compliance Parameters:

• Moisture Sensitivity Level: 1 (Unlimited)
• REACH Status: REACH Unaffected
• ECCN: EAR99

Substitute parts are categorized as follows:

Direct Manufacturer Equivalents: Parts meeting all electrical, functional, and physical specifications with identical or superior performance characteristics and active product status.

Parametric Equivalents: Parts with identical functional specifications but potentially different packaging formats or quiescent current ratings, suitable for direct substitution in most applications.

Similar Parts: Components with the same base product family (74AC series) but with minor variations in clock frequency, propagation delay, or supply voltage range that may require application-level verification.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Direct Replacement):

MC74AC74DR2G and MC74AC74DG are the preferred direct substitutes for the obsolete 74AC74SC. Both parts are manufactured by onsemi, maintain identical functional specifications, and are currently in active production status. MC74AC74DR2G is supplied in Tape & Reel packaging, while MC74AC74DG is supplied in Tube packaging. Both exhibit improved quiescent current performance (4 µA versus 20 µA) compared to the original part, resulting in lower power consumption. Both are RoHS3 compliant.

Secondary Substitutes (Texas Instruments):

SN74AC74DR and SN74AC74D are Texas Instruments equivalents offering superior electrical performance with reduced propagation delay (6 ns versus 10 ns) and lower quiescent current (2 µA). SN74AC74DR is currently active and available in Cut Tape & Digi-Reel packaging. SN74AC74D is discontinued at DiGi Electronics but remains available through alternative channels. Both are RoHS3 compliant.

SN74AC74MDREP is a Texas Instruments upgrade option with extended operating temperature range (-55°C to 125°C) and active product status, supplied in Tape & Reel packaging. This part is suitable for applications requiring wider temperature performance.

Similar Parts (Conditional Use):

74AC11074D and 74AC11074DR are similar parts with reduced clock frequency (150 MHz) and slightly higher propagation delay (7.5 ns). These parts operate within a narrower supply voltage range (3V to 5.5V) and are suitable only for applications where the reduced performance specifications are acceptable. 74AC11074DR is active; 74AC11074D is Last Time Buy status.

CD74AC74M96 operates at reduced clock frequency (100 MHz) with extended temperature range (-55°C to 125°C) and wider supply voltage range (1.5V to 5.5V). This part is suitable for low-frequency applications requiring extended environmental performance.

SN74AC74NSR is functionally equivalent to the main part but uses a wider 14-SOIC package (0.209" versus 0.154" width). Physical board layout compatibility must be verified before selection.

Frequently Asked Questions (FAQ)

Q: Can MC74AC74DR2G directly replace 74AC74SC without circuit modification?

A: Yes. MC74AC74DR2G maintains identical functional specifications, electrical performance parameters, and package dimensions. The improved quiescent current (4 µA versus 20 µA) represents a beneficial change with no negative impact on circuit operation.

Q: What is the difference between MC74AC74DR2G and MC74AC74DG?

A: Both parts are electrically and functionally identical. The difference is packaging format: MC74AC74DR2G is supplied in Tape & Reel (TR) format for automated assembly, while MC74AC74DG is supplied in Tube format for manual handling. Selection depends on assembly process requirements.

Q: Why does SN74AC74DR show lower propagation delay (6 ns) than the original part (10 ns)?

A: SN74AC74DR is a Texas Instruments design with superior electrical performance. The reduced propagation delay represents faster switching characteristics and is fully compatible with the original specification, which required a maximum of 10 ns. This is a beneficial improvement.

Q: Can 74AC11074D be used as a substitute?

A: 74AC11074D is a similar part with reduced clock frequency (150 MHz versus 160 MHz) and narrower supply voltage range (3V–5.5V versus 2V–6V). Substitution is possible only if the application operates within these reduced specifications. Verification of circuit requirements is necessary.

Q: What is the significance of the extended temperature range in SN74AC74MDREP?

A: SN74AC74MDREP operates from -55°C to 125°C, compared to -40°C to 85°C for the original part. This extended range is required only for applications with extreme environmental temperature requirements. Standard applications do not require this upgrade.

Q: Is SN74AC74NSR compatible with the original 14-SOIC footprint?

A: SN74AC74NSR uses a wider 14-SOIC package (0.209" width versus 0.154" width). Physical board layout compatibility must be verified. The part may not fit existing PCB footprints designed for the narrower package.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All active and recently discontinued substitute parts listed carry RoHS3 compliance certification. All parts maintain REACH Unaffected status and EAR99 ECCN classification.

Q: Which substitute offers the best power efficiency?

A: SN74AC74DR and SN74AC74D offer the lowest quiescent current at 2 µA, compared to 4 µA for onsemi parts and 20 µA for the original 74AC74SC. For power-sensitive applications, Texas Instruments parts provide superior efficiency.