LM2677S-3.3 Equivalent & Substitute Parts

Part Overview

The LM2677S-3.3 is a buck switching regulator IC from Texas Instruments, part of the SIMPLE SWITCHER® series. It delivers a fixed 3.3V output at 5A from an 8V to 40V input range, utilizing a 260kHz switching frequency topology. The device is housed in a TO-263-8 (D2PAK) surface mount package with 7 leads plus tab configuration.

The LM2677S-3.3 is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production or maintenance requirements for systems utilizing this regulator.

Substiute Parts

LM2677S-3.3

Texas InstrumentsIn Stock: 1487LM2677S-3.3 Datasheet

Current PartRFQ

LM2677S-3.3/NOPB

National SemiconductorIn Stock: 687LM2677S-3.3/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM2677S-3.3 is determined by strict equivalence across the following critical parameters:

• Output voltage specification: 3.3V fixed
• Output current rating: 5A minimum
• Input voltage operating range: 8V to 40V
• Switching frequency: 260kHz
• Package configuration: TO-263-8 (D2PAK-7)
• Mounting technology: Surface mount
• Operating temperature range: -40°C to 125°C

The LM2677S-3.3/NOPB qualifies as a direct substitute based on complete alignment with all specified electrical and mechanical parameters. This part maintains identical functional characteristics, pinout configuration, and thermal specifications required for direct board-level replacement.

Parameter Comparison

Engineering Selection Recommendations

The LM2677S-3.3/NOPB is the qualified substitute for the obsolete LM2677S-3.3. Both parts share identical electrical specifications and package configurations, enabling direct replacement without circuit modification.

The LM2677S-3.3/NOPB carries active product status, ensuring continued availability and manufacturing support. This part is ROHS3 compliant and REACH affected, representing current environmental and regulatory compliance standards. The original LM2677S-3.3 is non-compliant with RoHS requirements and carries unaffected REACH status, reflecting its obsolete classification.

For new designs or production transitions, the LM2677S-3.3/NOPB is the appropriate selection. For legacy system maintenance requiring the original part specification, the LM2677S-3.3 remains functionally equivalent where existing inventory is available.

Frequently Asked Questions (FAQ)

Q: Can the LM2677S-3.3/NOPB be used as a direct replacement for the LM2677S-3.3?

A: Yes. Both parts deliver identical electrical performance: 3.3V fixed output, 5A current rating, 8V to 40V input range, 260kHz switching frequency, and -40°C to 125°C operating temperature. The TO-263-8 (D2PAK-7) package configuration is identical, enabling direct board-level substitution without design changes.

Q: What is the significance of the "/NOPB" suffix in the LM2677S-3.3/NOPB part number?

A: The "/NOPB" suffix indicates "No Plumbum" (lead-free) packaging, reflecting RoHS3 compliance. This designation distinguishes the part from legacy lead-containing versions and confirms adherence to current environmental regulations.

Q: Why is the original LM2677S-3.3 classified as obsolete?

A: The LM2677S-3.3 is no longer in active production. The LM2677S-3.3/NOPB represents the current production equivalent, incorporating modern compliance standards while maintaining full functional compatibility.

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

A: No. Both parts operate within the same thermal specifications (-40°C to 125°C junction temperature) and deliver identical switching performance at 260kHz. Thermal management requirements and PCB layout considerations remain unchanged.

Q: What packaging considerations apply to both parts?

A: Both parts use the TO-263-8 (D2PAK-7) surface mount package with 7 leads plus tab. Pinout, pad layout, and thermal interface characteristics are identical. Existing PCB designs require no modification for substitution.