74AC74SJ Equivalent & Substitute Parts

Part Overview

The 74AC74SJ is a dual D-type flip-flop logic integrated circuit manufactured by onsemi, housed in a 14-SOIC surface mount 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 classified as obsolete, making identification of functionally equivalent alternatives essential for design continuity and procurement planning.

Substiute Parts

74AC74SJ

onsemiIn Stock: 222274AC74SJ Datasheet

Current PartRFQ

SN74AC74NSR

Texas InstrumentsIn Stock: 3440SN74AC74NSR Datasheet

DirectRFQ

74AC11074D

Texas InstrumentsIn Stock: 98174AC11074D Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74AC74SJ is determined by the following critical parameters:

Functional Equivalence Requirements:

• Base product number must be 74AC74 or 74AC11074 (same logic family and function)
• Type must be D-Type flip-flop with 2 elements, 1 bit per element
• Output type must be complementary
• Trigger type must be positive edge
• Function must include Set/Preset and Reset capability

Electrical Compatibility Requirements:

• Clock frequency must be ≥160 MHz
• Max propagation delay must be ≤10 ns @ 5V, 50pF
• Voltage supply range must encompass or match 2V ~ 6V
• Current output (High/Low) must be ≥24 mA / 24 mA
• Operating temperature range must include -40°C ~ 85°C

Physical Compatibility Requirements:

• Package type must be 14-SOIC
• Mounting type must be surface mount

Two substitute categories are identified:

Direct Substitutes (Identical Base Product Number 74AC74): Parts meeting all functional, electrical, and physical requirements with the same base product number.

Similar Substitutes (Related Base Product Number 74AC11074): Parts with different base product numbers but equivalent functional characteristics, requiring verification of specific parameter compatibility.

Parameter Comparison

Engineering Selection Recommendations

SN74AC74NSR (Direct Substitute - Recommended):

The SN74AC74NSR from Texas Instruments is a direct functional and electrical equivalent to the 74AC74SJ. This part maintains identical clock frequency (160 MHz), propagation delay (10 ns @ 5V, 50pF), voltage supply range (2V ~ 6V), and output current specifications (24 mA / 24 mA). The package dimensions are identical (14-SOIC, 0.209", 5.30mm width), ensuring PCB compatibility without layout modifications. The part is currently in active production status with ROHS3 compliance certification, providing long-term availability and regulatory alignment. Lower quiescent current (2 µA vs. 20 µA) and reduced input capacitance (3 pF vs. 4.5 pF) represent improved power efficiency characteristics.

74AC11074D (Similar Substitute - Conditional Use):

The 74AC11074D from Texas Instruments provides equivalent functional performance with superior electrical characteristics: faster propagation delay (7.5 ns vs. 10 ns) and lower quiescent current (4 µA vs. 20 µA). However, this part operates under a different base product number (74AC11074 vs. 74AC74) and exhibits a narrower voltage supply range (3V ~ 5.5V vs. 2V ~ 6V). The package width differs (0.154", 3.90mm vs. 0.209", 5.30mm), requiring PCB layout verification. Product status is Last Time Buy, indicating limited future availability. This substitute is suitable only when the narrower voltage range and different package dimensions are compatible with system requirements.

Frequently Asked Questions (FAQ)

Q: Can SN74AC74NSR be used as a direct replacement for 74AC74SJ without PCB modifications?

A: Yes. The SN74AC74NSR maintains identical electrical specifications and package dimensions (14-SOIC, 0.209", 5.30mm width). No PCB layout changes are required. Pin configuration and functional behavior are equivalent.

Q: What is the primary difference between the direct substitute (SN74AC74NSR) and the similar substitute (74AC11074D)?

A: The SN74AC74NSR uses base product number 74AC74 with voltage supply range 2V ~ 6V. The 74AC11074D uses base product number 74AC11074 with narrower voltage supply range 3V ~ 5.5V and different package width (0.154", 3.90mm vs. 0.209", 5.30mm). Both provide equivalent D-type flip-flop functionality with complementary outputs.

Q: Is the 74AC11074D suitable for applications requiring 2V supply operation?

A: No. The 74AC11074D operates within 3V ~ 5.5V supply range and cannot be used in applications requiring 2V minimum supply voltage. The SN74AC74NSR supports the full 2V ~ 6V range and is the appropriate choice for such applications.

Q: What are the compliance and availability implications of each substitute?

A: The SN74AC74NSR is in active production with ROHS3 compliance, ensuring long-term availability and regulatory alignment. The 74AC11074D is classified as Last Time Buy, indicating limited future procurement availability. For new designs, SN74AC74NSR is the preferred selection.

Q: How do quiescent current differences affect system design?

A: The 74AC74SJ draws 20 µA quiescent current, while SN74AC74NSR draws 2 µA and 74AC11074D draws 4 µA. In low-power applications or designs with multiple devices, the reduced quiescent current of the substitutes provides measurable power consumption benefits. This difference is not a functional incompatibility but rather an improvement in power efficiency.

Q: Are there package handling or moisture sensitivity differences between these parts?

A: All three parts are classified as Moisture Sensitivity Level (MSL) 1 (Unlimited), indicating no special moisture handling requirements. Standard surface mount assembly processes apply uniformly across all three parts.