LM2678T-3.3 Equivalent & Substitute Parts

Part Overview

The LM2678T-3.3 is a buck switching regulator IC from Texas Instruments' SIMPLE SWITCHER® series, designed for step-down voltage conversion with a fixed 3.3V output. This device delivers 5A output current and operates across an input voltage range of 8V to 40V, making it suitable for industrial and embedded power supply applications. The part is classified as obsolete, which necessitates identification of active equivalent alternatives to ensure design continuity and supply chain reliability.

Substiute Parts

LM2678T-3.3

Texas InstrumentsIn Stock: 4058LM2678T-3.3 Datasheet

Current PartRFQ

LM2678T-3.3/NOPB

Texas InstrumentsIn Stock: 1490LM2678T-3.3/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2678T-3.3 is determined by strict equivalence across the following electrical and mechanical parameters:

• Output voltage specification: 3.3V fixed
• Output current capability: 5A minimum
• Input voltage operating range: 8V to 40V
• Switching topology: Buck converter
• Package form factor: TO-220-7 Formed Leads
• Mounting configuration: Through Hole
• Operating temperature range: -40°C to 125°C (TJ)
• Base product series: LM2678

The LM2678T-3.3/NOPB qualifies as a direct substitute based on identical electrical specifications and mechanical compatibility. The primary distinction is product status and compliance certification.

Parameter Comparison

Engineering Selection Recommendations

The LM2678T-3.3/NOPB is the recommended substitute for the obsolete LM2678T-3.3. Both devices are electrically and mechanically identical, with all critical parameters matching across input voltage range, output specifications, switching characteristics, and thermal operating limits.

The LM2678T-3.3/NOPB offers two significant advantages:

• Product Status: Active production status ensures ongoing availability and supply chain continuity.
• Compliance: ROHS3 compliance satisfies modern regulatory requirements, whereas the original part carries non-compliant status.

Pin-for-pin compatibility and identical package geometry enable direct board-level substitution without circuit redesign. The /NOPB suffix indicates lead-free plating, which is standard for current production.

Frequently Asked Questions (FAQ)

Q: Can the LM2678T-3.3/NOPB be used as a direct replacement for LM2678T-3.3?

A: Yes. Both devices are electrically and mechanically identical. All electrical parameters, including output voltage, current rating, input voltage range, switching frequency, and operating temperature, are equivalent. The TO-220-7 package geometry is identical, enabling direct board-level substitution.

Q: What is the significance of the /NOPB suffix?

A: The /NOPB designation indicates lead-free plating on the device leads. This is the current manufacturing standard and reflects compliance with RoHS3 regulations. Functionally, the device operates identically to the original part.

Q: Why is the original LM2678T-3.3 listed as obsolete?

A: Obsolescence reflects Texas Instruments' discontinuation of this specific part number variant. The LM2678T-3.3/NOPB represents the active production equivalent with updated compliance certifications.

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

A: No. Operating temperature range, switching frequency, output current capability, and all electrical characteristics are identical. Thermal performance under equivalent operating conditions is the same.

Q: What packaging options are available for the substitute part?

A: The LM2678T-3.3/NOPB is supplied in Tube packaging. Both the original and substitute use the same TO-220-7 Formed Leads package type for board mounting.