LM3671MFX-ADJ Buck Switching Regulator IC

Part Overview

The LM3671MFX-ADJ is a buck switching regulator IC from Texas Instruments designed for positive adjustable output voltage regulation. This device functions as a step-down converter with a single adjustable output, delivering up to 600mA of output current. The part is classified as obsolete, making identification of suitable alternatives necessary for ongoing design support and procurement planning. The LM3671MFX-ADJ/NOPB variant provides an active production alternative with identical electrical and mechanical specifications.

Substiute Parts

LM3671MFX-ADJ

Texas InstrumentsIn Stock: 6886LM3671MFX-ADJ Datasheet

Current PartRFQ

LM3671MFX-ADJ/NOPB

Texas InstrumentsIn Stock: 23722LM3671MFX-ADJ/NOPB Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM3671MFX-ADJ is determined by the following critical parameters:

• Input voltage range: 2.7V to 5.5V
• Output voltage range: 1.1V to 3.3V (adjustable)
• Output current capacity: 600mA
• Switching frequency: 2MHz
• Synchronous rectifier topology: Yes
• Package type: SOT-23-5 (SC-74A, SOT-753)
• Operating temperature range: -40°C to 85°C

The LM3671MFX-ADJ/NOPB is a direct substitute, maintaining identical electrical specifications and mechanical packaging. The primary distinction is product status: the original part is obsolete, while the /NOPB variant is in active production.

Parameter Comparison

Engineering Selection Recommendations

The LM3671MFX-ADJ/NOPB is the appropriate selection for new designs and ongoing procurement. This variant maintains complete electrical and mechanical compatibility with the obsolete LM3671MFX-ADJ while offering the following advantages:

• Active production status ensures long-term availability and supply chain stability
• ROHS3 compliance satisfies current regulatory requirements, whereas the original part is RoHS non-compliant
• Identical electrical performance across all specified parameters
• Identical package and pinout configuration (SOT-23-5)

For legacy systems currently using the LM3671MFX-ADJ, direct replacement with the LM3671MFX-ADJ/NOPB requires no circuit modifications or re-qualification.

Frequently Asked Questions (FAQ)

Q: Can the LM3671MFX-ADJ/NOPB directly replace the LM3671MFX-ADJ in existing designs?

A: Yes. Both parts share identical electrical specifications, output voltage range (1.1V to 3.3V adjustable), output current (600mA), switching frequency (2MHz), and SOT-23-5 package configuration. No circuit modifications are required.

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

A: The /NOPB designation indicates the part is supplied without lead (Pb), reflecting RoHS3 compliance. The LM3671MFX-ADJ/NOPB is the production variant of the obsolete LM3671MFX-ADJ.

Q: Are there any compliance differences between these parts?

A: The LM3671MFX-ADJ/NOPB is ROHS3 compliant, while the original LM3671MFX-ADJ is RoHS non-compliant. Both maintain REACH Unaffected status. For applications subject to RoHS regulations, the /NOPB variant is required.

Q: What is the moisture sensitivity level for these parts?

A: Both parts carry MSL 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.

Q: Are the input and output voltage specifications identical?

A: Yes. Both parts accept input voltage from 2.7V to 5.5V and provide adjustable output voltage from 1.1V to 3.3V. Operating temperature range is identical at -40°C to 85°C.