74AC574SJ Equivalent & Substitute Parts

Part Overview

The 74AC574SJ is a D-Type flip-flop logic integrated circuit manufactured by onsemi, featuring 1 element with 8-bit positive edge triggering and tri-state non-inverted outputs. This component is classified as obsolete, which necessitates identification of active equivalent parts for ongoing design requirements and procurement continuity. The 74AC574 base product series maintains consistent functional characteristics across multiple manufacturers, enabling direct substitution based on electrical and mechanical parameter alignment.

Substiute Parts

74AC574SJ

onsemiIn Stock: 78174AC574SJ Datasheet

Current PartRFQ

CD74AC574M96

Texas InstrumentsIn Stock: 2823CD74AC574M96 Datasheet

SimilarRFQ

SN74AC574DWR

Texas InstrumentsIn Stock: 3871SN74AC574DWR Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 74AC574SJ is determined by the following critical parameters:

Functional Equivalence Requirements:

• D-Type flip-flop architecture with 1 element and 8-bit configuration
• Positive edge trigger mechanism
• Tri-state, non-inverted output configuration
• 74AC series classification

Electrical Compatibility Parameters:

• Clock frequency capability (minimum 153 MHz required)
• Propagation delay performance (maximum 9.5 ns @ 5V, 50pF)
• Voltage supply range overlap with 2V ~ 6V specification
• Output current capability (24 mA minimum for both high and low states)
• Operating temperature range compatibility

Mechanical Compatibility Parameters:

• Surface mount packaging format
• 20-pin SOIC package configuration
• Pin count and pinout alignment

The identified substitute parts CD74AC574M96 and SN74AC574DWR meet these functional and electrical criteria while maintaining the same base product number (74AC574) and package family classification.

Parameter Comparison

Engineering Selection Recommendations

SN74AC574DWR (Texas Instruments) - Primary Substitute

The SN74AC574DWR is the preferred substitute for the 74AC574SJ. This part maintains identical voltage supply range (2V ~ 6V), operating temperature range (-40°C ~ 85°C), clock frequency (153 MHz), and input capacitance (4.5 pF) specifications. The propagation delay performance is superior at 6 ns compared to the original 9.5 ns specification. The part holds active product status with RoHS3 compliance certification, ensuring long-term availability and regulatory alignment. Quiescent current is reduced to 4 µA, providing improved power efficiency.

CD74AC574M96 (Texas Instruments) - Secondary Substitute

The CD74AC574M96 functions as an alternative substitute with active product status and extended operating temperature range (-55°C ~ 125°C). This part meets the minimum clock frequency requirement at 125 MHz and maintains compatible output current specifications. The propagation delay at 10.8 ns exceeds the original specification by 1.3 ns but remains within acceptable tolerance for most 74AC logic applications. Quiescent current is significantly reduced to 8 µA. The voltage supply range is narrower (1.5V ~ 5.5V), which may limit applicability in systems requiring the full 2V ~ 6V range. RoHS3 compliance is confirmed.

Package Consideration

Both substitute parts utilize 20-SOIC packaging with 0.295" (7.50mm) width, compared to the original 0.209" (5.30mm) width. This dimensional difference requires PCB layout verification to ensure mechanical compatibility with existing footprints.

Frequently Asked Questions (FAQ)

Q: Can the CD74AC574M96 be used in applications requiring the full 2V ~ 6V supply voltage range?

A: The CD74AC574M96 voltage supply range is 1.5V ~ 5.5V, which does not fully overlap the original 2V ~ 6V specification. Applications requiring operation above 5.5V cannot use this substitute. The SN74AC574DWR maintains the complete 2V ~ 6V range and is the appropriate choice for such applications.

Q: What is the impact of the different package dimensions between the original and substitute parts?

A: The original 74AC574SJ uses a 20-SOIC package with 0.209" (5.30mm) width, while both substitutes use 0.295" (7.50mm) width. This dimensional difference requires PCB footprint verification. The pin count and spacing remain consistent within the 20-SOIC family, but the overall package body width is larger. PCB layout modifications may be necessary to accommodate the wider package body.

Q: How do the propagation delay differences affect circuit performance?

A: The SN74AC574DWR provides superior propagation delay at 6 ns, improving timing margins. The CD74AC574M96 at 10.8 ns exceeds the original 9.5 ns specification by 1.3 ns. For timing-critical applications operating near maximum frequency limits, the SN74AC574DWR is the preferred choice. The CD74AC574M96 remains suitable for applications with less stringent timing requirements.

Q: Are both substitute parts RoHS compliant?

A: Both the CD74AC574M96 and SN74AC574DWR are RoHS3 compliant. The original 74AC574SJ does not specify RoHS status. Both substitutes meet current regulatory requirements for electronic component manufacturing and distribution.

Q: What is the significance of the quiescent current reduction in the substitute parts?

A: The original 74AC574SJ specifies 40 µA quiescent current, while the SN74AC574DWR operates at 4 µA and the CD74AC574M96 at 8 µA. This reduction represents improved power efficiency in standby or low-activity states. For battery-powered or power-constrained applications, the substitute parts provide measurable power consumption benefits.

Q: Can these parts be used interchangeably on the same PCB?

A: Functional interchangeability is confirmed based on electrical specifications and pin configuration. However, the package dimension difference (0.209" versus 0.295" width) requires PCB footprint compatibility verification. If the original PCB footprint accommodates the wider 0.295" package, direct substitution is possible. Otherwise, PCB layout modification is necessary.