74ACTQ74SJ Equivalent & Substitute Parts

Part Overview

The 74ACTQ74SJ 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 2-element D-type flip-flop with complementary outputs, positive edge triggering, and set/reset capabilities. The device is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and new design implementations where this logic function is required.

Substiute Parts

74ACTQ74SJ

onsemiIn Stock: 88574ACTQ74SJ Datasheet

Current PartRFQ

SN74ACT74NSR

Texas InstrumentsIn Stock: 3874SN74ACT74NSR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74ACTQ74SJ is determined by strict equivalence across the following critical parameters:

• Logic Function: Dual D-type flip-flop with 2 elements, 1 bit per element, complementary outputs, and positive edge triggering
• Electrical Specifications: Supply voltage range 4.5V ~ 5.5V, operating temperature -40°C ~ 85°C
• Package Compatibility: 14-SOIC (0.209", 5.30mm Width) surface mount package
• Output Characteristics: 24mA output drive capability (high and low)
• Control Functions: Set(Preset) and Reset capability

The SN74ACT74NSR from Texas Instruments meets all these criteria and is classified as an active product, making it a direct functional and pin-compatible substitute for the obsolete 74ACTQ74SJ.

Parameter Comparison

Engineering Selection Recommendations

The SN74ACT74NSR is the direct substitute for the 74ACTQ74SJ based on functional equivalence and package compatibility. The substitute part offers the following advantages:

• Active Product Status: The SN74ACT74NSR is actively manufactured and supported by Texas Instruments, ensuring long-term availability and supply chain stability compared to the obsolete 74ACTQ74SJ.
• Improved Power Efficiency: Quiescent current is reduced from 20 µA to 2 µA, resulting in lower standby power consumption.
• Enhanced Compliance: The SN74ACT74NSR carries ROHS3 compliance certification, meeting modern environmental and regulatory requirements.
• Identical Electrical Interface: Both parts operate within the same supply voltage range (4.5V ~ 5.5V), temperature range (-40°C ~ 85°C), and output drive specifications (24mA).
• Pin and Package Compatibility: Both devices use the 14-SOIC (0.209", 5.30mm Width) package, enabling direct board-level substitution without layout modifications.

The marginal increase in propagation delay (8ns to 11ns) and reduction in input capacitance (4.5 pF to 3 pF) are within acceptable tolerances for standard logic applications and do not impact functional compatibility.

Frequently Asked Questions (FAQ)

Q: Can the SN74ACT74NSR be used as a direct replacement for the 74ACTQ74SJ without circuit modifications?

A: Yes. Both parts are pin-compatible D-type flip-flops in the 14-SOIC package with identical logic functions, output types, trigger mechanisms, and electrical operating ranges. No circuit modifications are required for substitution.

Q: What is the significance of the propagation delay difference between the two parts?

A: The 74ACTQ74SJ has a maximum propagation delay of 8ns at 5V with 50pF load, while the SN74ACT74NSR specifies 11ns under the same conditions. This 3ns difference is negligible for most digital logic applications operating at standard clock frequencies and does not affect functional compatibility.

Q: Why is the quiescent current lower in the SN74ACT74NSR?

A: The SN74ACT74NSR exhibits 2 µA quiescent current compared to 20 µA in the 74ACTQ74SJ. This represents improved power efficiency in the Texas Instruments design and results in lower standby power consumption, particularly beneficial in battery-powered or power-sensitive applications.

Q: Are there any compliance or certification differences between these parts?

A: The SN74ACT74NSR carries ROHS3 compliance certification, meeting current environmental regulations. Both parts have identical Moisture Sensitivity Level (MSL) ratings of 1 (Unlimited) and REACH Unaffected status. The substitute part is better suited for applications requiring modern compliance documentation.

Q: Is the package footprint identical between the 74ACTQ74SJ and SN74ACT74NSR?

A: Yes. Both parts use the 14-SOIC (0.209", 5.30mm Width) surface mount package with identical pin spacing and dimensions, enabling direct PCB-level substitution without layout changes.

Q: What is the availability status of each part?

A: The 74ACTQ74SJ is classified as obsolete and has limited availability (857 pcs reported in stock). The SN74ACT74NSR is an active product with robust supply availability (3799 pcs reported in stock) and ongoing manufacturing support from Texas Instruments.