LM3674MF-1.2 Equivalent & Substitute Parts

Part Overview

The LM3674MF-1.2 is a buck switching regulator IC from Texas Instruments, delivering a fixed 1.2V output at 600mA with a 2MHz switching frequency. This device is classified as obsolete, making equivalent and substitute parts necessary for new designs and production continuity. The part operates across a 2.7V to 5.5V input range with synchronous rectification and is housed in a SC-74A (SOT-753) package.

Substiute Parts

LM3674MF-1.2

Texas InstrumentsIn Stock: 6536LM3674MF-1.2 Datasheet

Current PartRFQ

LM3674MF-1.2/NOPB

Texas InstrumentsIn Stock: 1147LM3674MF-1.2/NOPB Datasheet

DirectRFQ

ADP2108AUJZ-1.2-R7

Analog Devices Inc.In Stock: 18099ADP2108AUJZ-1.2-R7 Datasheet

MFR RecommendedRFQ

MCP1603T-120I/OS

Microchip TechnologyIn Stock: 4498MCP1603T-120I/OS Datasheet

MFR RecommendedRFQ

RT8009-12GB

Richtek USA Inc.In Stock: 4552RT8009-12GB Datasheet

MFR RecommendedRFQ

RT8009-12GJ5

Richtek USA Inc.In Stock: 18840RT8009-12GJ5 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the LM3674MF-1.2 is determined by the following critical parameters:

• Fixed output voltage of 1.2V
• Output current capability of 600mA or greater
• Input voltage range compatibility (minimum 2.7V, maximum 5.5V)
• Buck topology with synchronous rectification
• Surface mount packaging in SOT-23-5 or equivalent footprint
• Single output configuration

Parts are grouped into two categories: direct equivalents (same manufacturer, active status) and manufacturer-recommended alternatives (different manufacturers, active status with enhanced specifications).

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent (Preferred for Pin-Compatible Replacement)

LM3674MF-1.2/NOPB is the direct equivalent from Texas Instruments. This part maintains identical electrical specifications and package configuration while offering active product status and RoHS3 compliance. Selection of this part eliminates design changes and provides the most straightforward migration path from the obsolete LM3674MF-1.2.

Manufacturer-Recommended Alternatives

ADP2108AUJZ-1.2-R7 (Analog Devices Inc.) provides enhanced operating temperature range (-40°C to 125°C) and higher switching frequency (3MHz), with a lower minimum input voltage (2.3V). Package migration to TSOT-23-5 is required.

MCP1603T-120I/OS (Microchip Technology) delivers equivalent input voltage range and switching frequency with extended operating temperature. Output current is rated at 500mA, which is below the original 600mA specification. Package migration to TSOT-23-5 is required.

RT8009-12GB and RT8009-12GJ5 (Richtek USA Inc.) maintain 600mA output current with lower minimum input voltage (2.5V) and reduced switching frequency (1.25MHz). RT8009-12GB uses SC-74A packaging; RT8009-12GJ5 uses TSOT-23-5 packaging. Both offer active status and RoHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can LM3674MF-1.2/NOPB be used as a direct replacement for LM3674MF-1.2?

A: Yes. LM3674MF-1.2/NOPB is electrically and mechanically identical to the original part, with identical pin configuration, package footprint, and electrical specifications. The primary difference is active product status and RoHS3 compliance.

Q: What is the key difference between RT8009-12GB and RT8009-12GJ5?

A: Both parts are from Richtek USA Inc. with identical electrical specifications. RT8009-12GB uses SC-74A (SOT-753) packaging, while RT8009-12GJ5 uses SOT-23-5 Thin (TSOT-23-5) packaging. Package selection depends on PCB layout and design requirements.

Q: Is MCP1603T-120I/OS a suitable substitute if the application requires 600mA output?

A: MCP1603T-120I/OS is rated for 500mA output current, which is below the original 600mA specification. This part is suitable only for applications where the actual load current does not exceed 500mA.

Q: What are the thermal operating range differences among substitutes?

A: The original LM3674MF-1.2 operates from -30°C to 85°C. ADP2108AUJZ-1.2-R7 and MCP1603T-120I/OS extend the upper limit to 125°C. RT8009 variants operate to 85°C. Selection depends on application thermal requirements.

Q: Do all substitute parts require PCB layout changes?

A: LM3674MF-1.2/NOPB requires no layout changes. ADP2108AUJZ-1.2-R7, MCP1603T-120I/OS, and RT8009-12GJ5 use TSOT-23-5 packaging, which may require minor footprint adjustments. RT8009-12GB maintains SC-74A packaging compatibility with the original part.