SN74LS174D Equivalent & Substitute Parts

Part Overview

The SN74LS174D is a Flip Flop 1 Element D-Type 6 Bit Positive Edge logic integrated circuit manufactured by Texas Instruments in the 74LS series. This component functions as a master reset device with non-inverted output, designed for digital logic applications requiring edge-triggered data capture and storage. The SN74LS174D is currently in Last Time Buy status, indicating discontinued production. Identifying equivalent substitute parts is necessary to ensure design continuity and maintain supply chain reliability for ongoing production and maintenance applications.

Substiute Parts

SN74LS174D

Texas InstrumentsIn Stock: 1080SN74LS174D Datasheet

Current PartRFQ

SN74LS174DR

Texas InstrumentsIn Stock: 3783SN74LS174DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS174D is determined by strict equivalence across the following critical parameters:

• Functional Type: D-Type Flip Flop with 1 Element, 6 Bits per Element
• Electrical Performance: Clock Frequency 40 MHz, Propagation Delay 30 ns @ 5V/15pF, Positive Edge Trigger
• Output Characteristics: Non-Inverted output, Current ratings 400µA (High) / 8mA (Low)
• Power Supply: 4.75V ~ 5.25V operating range
• Package Compatibility: 16-SOIC (0.154", 3.90mm Width) surface mount
• Compliance: ROHS3 Compliant, MSL Level 1

The SN74LS174DR qualifies as a direct substitute based on identical electrical specifications, functional characteristics, and package form factor. The primary distinction is packaging format: the SN74LS174D is supplied in Tube packaging, while the SN74LS174DR is supplied in Tape & Reel (TR) format.

Parameter Comparison

Engineering Selection Recommendations

The SN74LS174DR is the direct substitute for the SN74LS174D. Both components are manufactured by Texas Instruments and maintain identical electrical, functional, and mechanical specifications. The SN74LS174DR holds Active product status, ensuring continued availability and supply chain support, whereas the SN74LS174D is in Last Time Buy status.

Selection between these parts is determined by packaging requirements:

• SN74LS174D (Tube packaging): Suitable for lower-volume applications, manual assembly, or existing inventory management where tube format is preferred.
• SN74LS174DR (Tape & Reel packaging): Recommended for high-volume production, automated pick-and-place assembly, and new designs requiring continuous supply assurance.

Both parts maintain ROHS3 compliance and MSL Level 1 rating, ensuring compatibility with modern manufacturing processes and environmental regulations.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS174DR directly replace the SN74LS174D in existing designs?

A: Yes. The SN74LS174DR is electrically and functionally identical to the SN74LS174D. Both components feature identical pin configurations, electrical performance, and mechanical dimensions in the 16-SOIC package. The only difference is the packaging format (Tape & Reel versus Tube).

Q: What is the difference between Tube and Tape & Reel packaging?

A: Tube packaging supplies components in plastic tubes suitable for manual handling and lower-volume applications. Tape & Reel packaging supplies components on continuous carrier tape wound on reels, optimized for automated assembly equipment and high-volume production. Both formats contain the same component with identical specifications.

Q: Why is the SN74LS174D listed as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued production of this part number. The SN74LS174DR remains in Active status and is the recommended replacement for new designs and ongoing production requirements.

Q: Are there any electrical performance differences between these parts?

A: No. Both the SN74LS174D and SN74LS174DR maintain identical clock frequency (40 MHz), propagation delay (30 ns @ 5V, 15pF), supply voltage range (4.75V ~ 5.25V), output current ratings (400µA High, 8mA Low), and quiescent current (26 mA).

Q: Do both parts meet the same compliance standards?

A: Yes. Both the SN74LS174D and SN74LS174DR are ROHS3 Compliant with MSL Level 1 rating, ensuring compatibility with current manufacturing and environmental requirements.

Q: Can I use the SN74LS174DR in existing PCB designs that specify the SN74LS174D?

A: Yes, provided the PCB footprint and assembly process accommodate Tape & Reel packaging. The 16-SOIC package dimensions are identical, and the component pinout is unchanged. Verify that your assembly equipment supports reel-fed components if transitioning from tube to Tape & Reel format.