74ACTQ74SJX Equivalent & Substitute Parts

Part Overview

The 74ACTQ74SJX is a dual D-type flip-flop logic integrated circuit manufactured by onsemi, housed in a 14-SOIC surface mount package. This component provides two independent D-type flip-flops with complementary outputs, set/preset and reset functionality, and positive edge triggering. The part is currently obsolete, making equivalent substitutes necessary for ongoing production and maintenance applications requiring this logic function.

Substiute Parts

74ACTQ74SJX

onsemiIn Stock: 96474ACTQ74SJX Datasheet

Current PartRFQ

SN74ACT74NSR

Texas InstrumentsIn Stock: 3874SN74ACT74NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74ACTQ74SJX is determined by strict alignment of the following critical parameters:

• Logic Function: Dual D-type flip-flop with complementary outputs, set/preset and reset capability
• Trigger Mechanism: Positive edge triggering
• Package Type: 14-SOIC (0.209", 5.30mm Width) surface mount
• Electrical Specifications: Supply voltage range 4.5V ~ 5.5V, operating temperature -40°C ~ 85°C
• Output Characteristics: 24mA output current capability (high and low)
• Pin Configuration: Identical pinout and functional pin assignment

The SN74ACT74NSR from Texas Instruments meets all these criteria, providing functional and electrical equivalence within the specified parameter constraints.

Parameter Comparison

Engineering Selection Recommendations

The SN74ACT74NSR is a direct functional substitute for the 74ACTQ74SJX. Both components share identical package geometry, pinout, and core logic specifications. The substitute offers the following advantages:

• Active Product Status: The SN74ACT74NSR is in active production, ensuring long-term availability and supply chain continuity
• Regulatory Compliance: RoHS3 compliant, meeting current environmental and regulatory requirements
• Improved Performance Characteristics: Lower quiescent current (2 µA vs. 20 µA) and reduced input capacitance (3 pF vs. 4.5 pF) provide marginal efficiency gains
• Equivalent Electrical Performance: Propagation delay, output current, supply voltage, and operating temperature ranges are compatible with the original specification

Selection of the SN74ACT74NSR is appropriate for new designs, production restarts, and maintenance applications requiring the 74ACTQ74SJX function.

Frequently Asked Questions (FAQ)

Q: Can the SN74ACT74NSR be used as a direct replacement for the 74ACTQ74SJX?

A: Yes. Both parts are housed in identical 14-SOIC packages with matching pinouts and functional specifications. No circuit modifications or PCB layout changes are required.

Q: Are there differences in propagation delay between these parts?

A: The SN74ACT74NSR has a maximum propagation delay of 11ns at 5V with 50pF load, compared to 8ns for the 74ACTQ74SJX. Both values are within acceptable timing margins for standard logic applications operating at the specified clock frequencies.

Q: What is the significance of the lower quiescent current in the SN74ACT74NSR?

A: The SN74ACT74NSR draws 2 µA quiescent current versus 20 µA for the 74ACTQ74SJX. This reduction is beneficial for low-power or battery-operated applications, though both values are typical for CMOS logic circuits in this family.

Q: Are there any package or mounting differences?

A: No. Both parts use the 14-SOIC (0.209", 5.30mm Width) surface mount package with identical lead spacing and dimensions. PCB footprints are interchangeable.

Q: Why is the 74ACTQ74SJX obsolete?

A: The 74ACTQ74SJX is an older onsemi product. The SN74ACT74NSR from Texas Instruments provides equivalent functionality and is actively manufactured, making it the preferred choice for current applications.

Q: Are there compliance or certification differences?

A: The SN74ACT74NSR is RoHS3 compliant. Both parts are REACH unaffected and carry MSL 1 (Unlimited) moisture sensitivity ratings. The substitute meets current environmental and regulatory standards.