SN74ALS174D Equivalent & Substitute Parts

Part Overview

The SN74ALS174D is a flip-flop logic integrated circuit manufactured by Texas Instruments, classified as a D-Type flip-flop with 1 element and 6 bits per element. This component operates as a master reset device with positive edge triggering and non-inverted outputs. The device is currently in Last Time Buy status, indicating discontinued production. Finding equivalent substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications requiring this specific logic function.

Substiute Parts

SN74ALS174D

Texas InstrumentsIn Stock: 2640SN74ALS174D Datasheet

Current PartRFQ

SN74ALS174DR

Texas InstrumentsIn Stock: 5717SN74ALS174DR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74ALS174D is determined by strict equivalence across the following critical parameters:

• Logic Function: D-Type flip-flop with 1 element and 6 bits per element
• Electrical Performance: Clock frequency of 50 MHz, propagation delay of 17 ns @ 5V with 50pF load
• Trigger Characteristics: Positive edge triggering with non-inverted outputs
• Power Supply: 4.5V to 5.5V operating range
• Output Specifications: 400µA high current and 8mA low current capability
• Package Compatibility: 16-SOIC surface mount package with 0.154" (3.90mm) width
• Compliance Requirements: ROHS3 compliance and MSL Level 1

The substitute part SN74ALS174DR meets all these criteria with identical electrical and mechanical specifications. The primary difference is packaging format: the main part uses Tube packaging while the substitute uses Tape & Reel (TR) packaging. Both are surface mount 16-SOIC packages with identical pinouts and electrical characteristics.

Parameter Comparison

Engineering Selection Recommendations

The SN74ALS174D is designated as Last Time Buy, indicating end-of-life status. The SN74ALS174DR is the direct equivalent substitute, currently in Active production status from Texas Instruments. Both parts are ROHS3 compliant and carry MSL Level 1 rating, meeting environmental and reliability standards.

Selection between these parts is determined by packaging requirements and supply chain considerations. The SN74ALS174DR in Tape & Reel format is suitable for high-volume automated assembly processes, while the tube-packaged SN74ALS174D is appropriate for lower-volume or manual assembly operations. Since the main part is Last Time Buy, the SN74ALS174DR is the recommended long-term solution for continued production and new designs.

All electrical and mechanical parameters are identical, ensuring direct functional equivalence with no circuit redesign required.

Frequently Asked Questions (FAQ)

Q: Can SN74ALS174DR be used as a direct replacement for SN74ALS174D?

A: Yes. Both parts are electrically and mechanically identical. They share the same 16-SOIC package, pinout, electrical specifications, and operating characteristics. The only difference is packaging format: Tube versus Tape & Reel.

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

A: Tube packaging is used for lower-volume applications and manual assembly, while Tape & Reel packaging is designed for automated pick-and-place assembly in high-volume production. The components themselves are identical.

Q: Why is the SN74ALS174D marked as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments has discontinued this product line. The SN74ALS174DR in Tape & Reel format is the active production equivalent and should be used for new designs and ongoing production.

Q: Are there any compliance differences between these parts?

A: No. Both parts are ROHS3 compliant, REACH unaffected, and carry MSL Level 1 rating. They meet identical environmental and regulatory standards.

Q: What are the critical parameters for substitution compatibility?

A: Substitution compatibility is determined by: D-Type flip-flop function with 1 element and 6 bits, 50 MHz clock frequency, 17 ns propagation delay, positive edge triggering, non-inverted outputs, 4.5V to 5.5V supply range, 16-SOIC surface mount package, and identical output current specifications.

Q: Can these parts be used interchangeably in existing PCB designs?

A: Yes. The identical 16-SOIC package and pinout allow direct substitution on existing PCBs without layout modifications. No circuit changes are required.