SN74LS377DW Equivalent & Substitute Parts

Part Overview

The SN74LS377DW is a D-Type flip-flop logic integrated circuit manufactured by Texas Instruments, designed for 8-bit parallel data storage and transfer applications. This component features a single D-type flip-flop element with 8-bit capacity, positive edge triggering, and operates at a maximum clock frequency of 40 MHz. The device is packaged in a 20-SOIC surface mount configuration with a 0.295" (7.50mm) width.

The SN74LS377DW is currently discontinued at DiGi Electronics, making equivalent substitute parts necessary for ongoing production, maintenance, and design continuity. Identifying compatible alternatives ensures project timelines remain unaffected while maintaining electrical and mechanical compatibility.

Substiute Parts

SN74LS377DW

Texas InstrumentsIn Stock: 1265SN74LS377DW Datasheet

Current PartRFQ

SN74LS377DWR

Texas InstrumentsIn Stock: 978SN74LS377DWR Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the SN74LS377DW is determined by strict equivalence across the following critical parameters:

Electrical Compatibility Requirements:

• Identical logic function (D-Type flip-flop, 8-bit, single element)
• Matching clock frequency specification (40 MHz minimum)
• Identical propagation delay characteristics (27ns @ 5V, 15pF)
• Matching trigger type (Positive Edge)
• Identical output configuration (Non-Inverted)
• Matching supply voltage range (4.75V ~ 5.25V)
• Equivalent current specifications (Output High/Low, Quiescent current)

Mechanical Compatibility Requirements:

• Identical package type (20-SOIC with 0.295", 7.50mm width)
• Surface mount configuration
• Same pin count and pinout arrangement

Compliance Requirements:

• RoHS3 compliance maintained
• MSL rating of 1 or better
• REACH compliance status

The SN74LS377DWR qualifies as a direct substitute based on identical electrical specifications and package configuration. The primary difference is packaging format (Tape & Reel versus Tube) and product status (Active versus Discontinued).

Parameter Comparison

Engineering Selection Recommendations

The SN74LS377DWR is a direct functional and mechanical equivalent to the SN74LS377DW. Selection between these parts should be based on the following engineering criteria:

Product Status Consideration: The SN74LS377DWR maintains Active product status with Texas Instruments, ensuring continued availability, technical support, and manufacturing consistency. The SN74LS377DW is discontinued, limiting future procurement options.

Compliance and Certification: Both parts maintain identical RoHS3 compliance, MSL rating of 1, and REACH compliance status, meeting regulatory requirements for industrial and commercial applications.

Packaging and Supply Chain: The SN74LS377DWR is supplied in Tape & Reel format, standard for automated assembly and high-volume production. The SN74LS377DW is supplied in Tube format, suitable for lower-volume or manual assembly operations. Selection depends on production methodology and volume requirements.

Quiescent Current Variance: The SN74LS377DWR exhibits a quiescent current of 28 mA compared to 18 mA for the SN74LS377DW. This 10 mA difference is within acceptable tolerance for 74LS series logic devices and does not affect functional compatibility. Power budget analysis should account for this variance in low-power or battery-operated applications.

Recommendation: For new designs and ongoing production, the SN74LS377DWR is the preferred selection due to active product status and assured long-term availability. Existing designs using the SN74LS377DW can transition to the SN74LS377DWR without circuit modification, provided supply chain and packaging format requirements are accommodated.

Frequently Asked Questions (FAQ)

Q: Can the SN74LS377DWR be used as a direct replacement for the SN74LS377DW in existing circuit designs?

A: Yes. The SN74LS377DWR is electrically and mechanically equivalent to the SN74LS377DW. Both devices share identical pinout, electrical specifications, and functional characteristics. No circuit modifications are required for substitution.

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

A: Tube packaging contains individual components in a plastic tube, suitable for manual assembly and lower-volume applications. Tape & Reel packaging places components on a continuous tape wound on a reel, optimized for automated pick-and-place assembly equipment. The electrical and functional performance of the component is identical regardless of packaging format.

Q: Does the quiescent current difference between the two parts affect circuit performance?

A: The quiescent current difference (18 mA versus 28 mA) represents a 10 mA variance within normal 74LS series tolerance. This difference does not affect functional operation or signal integrity. For applications with strict power budget constraints, power consumption calculations should account for this variance.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the SN74LS377DW and SN74LS377DWR are RoHS3 compliant with MSL rating of 1 (Unlimited), meeting regulatory requirements for industrial, commercial, and consumer applications.

Q: What is the operating temperature range for these devices?

A: Both parts operate across the temperature range of 0°C to 70°C (TA). This specification applies to both the main part and substitute, ensuring consistent performance across standard industrial operating conditions.

Q: Why is the SN74LS377DW discontinued?

A: Product discontinuation decisions are made by manufacturers based on market demand, technology evolution, and production priorities. The SN74LS377DWR remains in active production, providing continuity for applications requiring this logic function.

Q: Can these parts be used interchangeably in automated assembly?

A: The SN74LS377DWR in Tape & Reel format is optimized for automated assembly. The SN74LS377DW in Tube format requires manual handling or custom feeder equipment. Both are mechanically compatible with standard 20-SOIC pick-and-place tooling, but supply format should align with assembly methodology.