SN74AS874NT Equivalent & Substitute Parts

Part Overview

The SN74AS874NT is a dual 4-bit D-type flip-flop logic integrated circuit manufactured by Texas Instruments in the 74AS series. This component functions as a master reset flip-flop with tri-state, non-inverted outputs, designed for digital logic applications requiring edge-triggered data storage and control. The SN74AS874NT is classified as obsolete, making identification of functionally equivalent substitute parts essential for ongoing system maintenance, repair, and redesign efforts where component availability is constrained.

Substiute Parts

SN74AS874NT

Texas InstrumentsIn Stock: 3597SN74AS874NT Datasheet

Current PartRFQ

SN74AS874DW

Texas InstrumentsIn Stock: 775SN74AS874DW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74AS874NT is determined by strict equivalence across the following electrical and mechanical parameters:

Electrical Equivalence Criteria:

• Series: 74AS (identical logic family)
• Type: D-Type Flip-Flop (identical function)
• Number of Elements: 2 (identical configuration)
• Number of Bits per Element: 4 (identical bit width)
• Function: Master Reset (identical control function)
• Output Type: Tri-State, Non-Inverted (identical output characteristics)
• Clock Frequency: 125 MHz (identical timing specification)
• Max Propagation Delay: 10.5ns @ 5V, 50pF (identical timing performance)
• Trigger Type: Positive Edge (identical edge sensitivity)
• Voltage - Supply: 4.5V ~ 5.5V (identical supply range)
• Current - Output High, Low: 15mA, 48mA (identical output drive capability)
• Current - Quiescent (Iq): 133 mA (identical standby current)
• Operating Temperature: 0°C ~ 70°C (TA) (identical temperature range)

Mechanical Equivalence Criteria:

• Base Product Number: 74AS874 (identical base design)
• RoHS Status: ROHS3 Compliant (identical environmental compliance)
• Moisture Sensitivity Level (MSL): 1 (Unlimited) (identical moisture rating)

The primary distinction between the main part and substitute parts is the package type and mounting technology. The SN74AS874NT uses through-hole mounting in a 24-DIP package, while substitute parts may employ surface-mount technology in alternative package configurations. All electrical parameters remain identical across the product family.

Parameter Comparison

Engineering Selection Recommendations

The SN74AS874DW is the manufacturer-recommended substitute for the obsolete SN74AS874NT. Both components maintain identical electrical specifications, including clock frequency, propagation delay, output drive capability, supply voltage range, and quiescent current. The primary difference is packaging: the SN74AS874NT uses through-hole 24-DIP mounting, while the SN74AS874DW uses surface-mount 24-SOIC technology.

The SN74AS874DW carries active product status from Texas Instruments, ensuring ongoing availability and manufacturing support. Both parts maintain ROHS3 compliance and identical moisture sensitivity ratings, confirming environmental and regulatory equivalence.

Selection between these parts depends on board-level design requirements. Through-hole mounting (SN74AS874NT) is suitable for legacy systems or applications requiring manual assembly or rework accessibility. Surface-mount technology (SN74AS874DW) is appropriate for modern PCB designs utilizing automated assembly processes and higher component density layouts.

Frequently Asked Questions (FAQ)

Q: Can the SN74AS874DW directly replace the SN74AS874NT in existing designs?

A: Electrical substitution is complete. The SN74AS874DW provides identical logic function, timing performance, and electrical characteristics. Physical substitution requires PCB redesign to accommodate the different package footprint: 24-DIP (through-hole) versus 24-SOIC (surface-mount).

Q: What is the primary reason for substitution?

A: The SN74AS874NT is classified as obsolete. The SN74AS874DW is the active equivalent from the same manufacturer, ensuring continued component availability and manufacturing support.

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

A: No. Both parts share identical specifications for clock frequency (125 MHz), propagation delay (10.5ns @ 5V, 50pF), output drive capability (15mA high, 48mA low), supply voltage range (4.5V ~ 5.5V), and operating temperature (0°C ~ 70°C).

Q: What are the package differences?

A: The SN74AS874NT uses a 24-pin DIP (Dual In-line Package) with 0.300" (7.62mm) spacing for through-hole mounting. The SN74AS874DW uses a 24-pin SOIC (Small Outline Integrated Circuit) with 0.295" (7.50mm) width for surface-mount assembly.

Q: Do both parts meet the same compliance standards?

A: Yes. Both the SN74AS874NT and SN74AS874DW are ROHS3 compliant with identical moisture sensitivity levels (MSL 1 - Unlimited), confirming equivalent environmental and regulatory compliance.

Q: Which part should be selected for new designs?

A: The SN74AS874DW is the appropriate choice for new designs. It maintains active product status, ensuring long-term availability and manufacturing continuity. The SN74AS874NT should be reserved for legacy system maintenance where through-hole mounting is required.