SN74LS74ADBR Equivalent & Substitute Parts

Part Overview

The SN74LS74ADBR is a dual D-type flip-flop logic integrated circuit manufactured by Texas Instruments in the 74LS series. This component functions as a Set(Preset) and Reset element with complementary outputs, designed for positive edge triggering applications. The product is classified as Obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and production continuity. Substitute parts must maintain core functional characteristics including D-type flip-flop topology, dual element configuration, and complementary output capability while accommodating modern active-status alternatives.

Substiute Parts

SN74LS74ADBR

Texas InstrumentsIn Stock: 1598SN74LS74ADBR Datasheet

Current PartRFQ

SN74ACT74PWR

Texas InstrumentsIn Stock: 3913SN74ACT74PWR Datasheet

MFR RecommendedRFQ

74ABT74PW,118

Nexperia USA Inc.In Stock: 82774ABT74PW,118 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the SN74LS74ADBR are selected based on functional equivalence within the 74-series logic family. The core substitution criteria are:

Mandatory Functional Parameters:

• Dual D-type flip-flop configuration (2 elements, 1 bit per element)
• Complementary output topology
• Positive edge trigger mechanism
• Set(Preset) and Reset functionality

Electrical Compatibility Parameters:

• Supply voltage range overlap with 4.75V ~ 5.25V nominal operation
• Clock frequency capability equal to or exceeding 33 MHz
• Propagation delay performance suitable for timing-critical applications
• Output current drive capability compatible with load requirements

Physical & Compliance Parameters:

• Surface mount packaging in 14-pin configuration
• ROHS3 compliance maintained
• MSL rating of 1 or equivalent

The identified substitutes—SN74ACT74PWR (Texas Instruments, 74ACT series) and 74ABT74PW,118 (Nexperia USA Inc., 74ABT series)—meet these criteria while offering active product status and enhanced performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Both substitute parts maintain full functional compatibility with the SN74LS74ADBR while offering active product status and improved electrical performance.

SN74ACT74PWR is recommended for applications requiring Texas Instruments sourcing continuity. This part operates within an expanded supply voltage range (4.5V ~ 5.5V) and delivers significantly reduced propagation delay (11 ns) compared to the original specification. The 74ACT series provides lower quiescent current (2 µA) and higher clock frequency capability (210 MHz), making it suitable for power-sensitive and timing-critical designs. ROHS3 compliance and unlimited MSL rating ensure compatibility with modern manufacturing processes.

74ABT74PW,118 is recommended for applications prioritizing maximum performance and extended temperature operation. Manufactured by Nexperia USA Inc., this 74ABT series component offers the fastest propagation delay (4.2 ns) and highest clock frequency (250 MHz) among available substitutes. The expanded operating temperature range (-40°C ~ 85°C) accommodates industrial and automotive environments. Output current drive capability (15mA high, 20mA low) exceeds the original specification, supporting higher fan-out requirements. ROHS3 compliance and unlimited MSL rating are maintained.

Both substitutes employ 14-TSSOP packaging (0.173", 4.40mm Width), which is physically compatible with standard 14-pin surface mount footprints used for the original 14-SSOP package. PCB layout modifications are not required for package transition.

Frequently Asked Questions (FAQ)

Q: Can SN74ACT74PWR or 74ABT74PW,118 directly replace SN74LS74ADBR in existing designs?

A: Yes. Both substitutes maintain identical functional topology (dual D-type flip-flop with complementary outputs and positive edge triggering), supply voltage compatibility within the 4.75V ~ 5.25V nominal range, and surface mount 14-pin configuration. No circuit redesign is required. The 14-TSSOP package footprint is compatible with standard 14-pin surface mount layouts.

Q: What are the key performance improvements offered by the substitute parts?

A: SN74ACT74PWR reduces propagation delay from 40 ns to 11 ns and increases clock frequency capability from 33 MHz to 210 MHz. 74ABT74PW,118 provides further improvements with 4.2 ns propagation delay and 250 MHz clock frequency. Both substitutes reduce quiescent current consumption compared to the original 8 mA specification, improving power efficiency in battery-powered or thermally constrained applications.

Q: Are there packaging differences between the original and substitute parts?

A: The original SN74LS74ADBR uses 14-SSOP packaging (0.209" width), while both substitutes employ 14-TSSOP packaging (0.173" width). The TSSOP package is narrower but maintains the same 14-pin configuration and pin pitch. Standard 14-pin surface mount footprints accommodate both package types without PCB modification.

Q: Do the substitute parts maintain RoHS and compliance certifications?

A: Yes. Both SN74ACT74PWR and 74ABT74PW,118 are ROHS3 compliant with unlimited MSL rating (1), matching the original part's compliance status. Both are classified as REACH Unaffected and carry EAR99 ECCN designation.

Q: Which substitute should be selected for temperature-critical applications?

A: Both substitutes support extended operating temperature range (-40°C ~ 85°C) compared to the original specification (0°C ~ 70°C). For applications requiring maximum temperature margin and performance consistency across industrial or automotive environments, 74ABT74PW,118 is recommended due to its superior propagation delay stability and highest clock frequency capability.

Q: What is the supply voltage compatibility between the original and substitute parts?

A: The original SN74LS74ADBR operates within 4.75V ~ 5.25V. Both substitutes accept 4.5V ~ 5.5V, providing wider voltage tolerance. Designs operating at the original specification limits (4.75V ~ 5.25V) are fully compatible with both substitutes. The expanded range of substitute parts provides additional design margin for voltage regulation variations.