LM2678T-12 Equivalent & Substitute Parts

Part Overview

The LM2678T-12 is a buck switching regulator IC from Texas Instruments' SIMPLE SWITCHER® series, designed for step-down voltage conversion with a fixed 12V output and 5A current capacity. This device operates across an input voltage range of 15V to 40V and is housed in a TO-220-7 package with formed leads.

The LM2678T-12 carries an obsolete product status. Identifying equivalent and substitute parts is necessary to ensure design continuity, maintain supply chain reliability, and support long-term product availability for applications requiring this specific voltage regulation topology and performance characteristics.

Substiute Parts

LM2678T-12

Texas InstrumentsIn Stock: 5306LM2678T-12 Datasheet

Current PartRFQ

LM2678T-12/NOPB

Texas InstrumentsIn Stock: 1064LM2678T-12/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2678T-12 is determined by strict equivalence across the following critical parameters:

• Output voltage configuration (12V fixed)
• Output current rating (5A minimum)
• Input voltage operating range (15V to 40V)
• Switching frequency (260kHz)
• Package type and form factor (TO-220-7 Formed Leads)
• Mounting technology (Through Hole)
• Operating temperature range (-40°C to 125°C)
• Topology (Buck/Step-Down)

Parts meeting all these criteria are considered direct substitutes. Variations in packaging designation, RoHS compliance status, or product lifecycle stage do not affect functional equivalence when all electrical and mechanical parameters remain identical.

Parameter Comparison

Engineering Selection Recommendations

The LM2678T-12/NOPB is a direct functional equivalent to the LM2678T-12. Both parts share identical electrical specifications, switching characteristics, and mechanical packaging. The primary distinction is product lifecycle status: the LM2678T-12 is obsolete, while the LM2678T-12/NOPB maintains active status with current manufacturing support.

For new designs or ongoing production requiring this buck regulator topology, the LM2678T-12/NOPB is the appropriate selection. This part carries RoHS3 compliance, meeting modern regulatory requirements, whereas the original LM2678T-12 does not. Both parts are REACH Unaffected and classified under ECCN EAR99.

Current inventory availability differs: LM2678T-12 stock is 5228 units, while LM2678T-12/NOPB stock is 1002 units. Packaging differs by designation (unspecified for LM2678T-12 versus Tube for LM2678T-12/NOPB), but both use identical TO-220-7 Formed Leads package construction.

Frequently Asked Questions (FAQ)

Q: Can the LM2678T-12/NOPB replace the LM2678T-12 in existing applications?

A: Yes. Both parts are electrically and mechanically identical. The LM2678T-12/NOPB is the active production equivalent and is a direct substitute for the obsolete LM2678T-12.

Q: What does the "/NOPB" suffix indicate?

A: The "/NOPB" designation indicates the part is supplied without plumbum (lead-free), reflecting RoHS3 compliance. This is a packaging and compliance designation only and does not affect electrical performance or pin compatibility.

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

A: No. Both parts operate across the identical temperature range of -40°C to 125°C (TJ) and share the same TO-220-7 package, which determines thermal characteristics.

Q: Can I use either part interchangeably on the same PCB?

A: Yes. Both parts use the TO-220-7 Formed Leads package with identical pinout and mechanical dimensions. No PCB modifications are required for substitution.

Q: Why should I choose the LM2678T-12/NOPB over the LM2678T-12?

A: The LM2678T-12/NOPB is the recommended choice because it maintains active product status with ongoing manufacturing support and meets RoHS3 regulatory compliance. The LM2678T-12 is obsolete and should not be specified for new designs.

Q: What are the key parameters that define substitution eligibility?

A: Substitution is determined by matching output voltage (12V), output current (5A), input voltage range (15V–40V), switching frequency (260kHz), package type (TO-220-7 Formed Leads), and operating temperature range (-40°C to 125°C).