LM3478MM Equivalent & Substitute Parts

Part Overview

The LM3478MM is a boost, flyback, and SEPIC regulator controller IC manufactured by Texas Instruments, designed for positive output step-up and step-up/step-down DC-DC conversion applications. This device operates as a transistor driver with a single output phase and supports switching frequencies from 100kHz to 1MHz. The LM3478MM is currently in Last Time Buy status, indicating end-of-life production. Direct substitutes with active product status are available to ensure design continuity and supply chain reliability.

Substiute Parts

LM3478MM

Texas InstrumentsIn Stock: 6658LM3478MM Datasheet

Current PartRFQ

LM3478MM/NOPB

Texas InstrumentsIn Stock: 28216LM3478MM/NOPB Datasheet

DirectRFQ

LM3478MMX/NOPB

Texas InstrumentsIn Stock: 47210LM3478MMX/NOPB Datasheet

Parametric EquivalentRFQ

LM3478QMM/NOPB

Texas InstrumentsIn Stock: 31420LM3478QMM/NOPB Datasheet

Parametric EquivalentRFQ

LM3478QMMX/NOPB

Texas InstrumentsIn Stock: 17403LM3478QMMX/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM3478MM is determined by strict equivalence across the following critical parameters:

• Topology: Boost, Flyback, SEPIC
• Output Type: Transistor Driver
• Output Configuration: Positive
• Voltage Supply Range: 2.97V ~ 40V
• Switching Frequency Range: 100kHz ~ 1MHz
• Duty Cycle Maximum: 100%
• Control Features: Enable, Frequency Control
• Operating Temperature Range: -40°C ~ 125°C (TJ)
• Package / Case: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
• Supplier Device Package: 8-VSSOP

All substitute parts listed maintain identical electrical specifications and package dimensions. Differences exist only in product status, packaging format (Cut Tape vs. Tape & Reel), and automotive qualification grades where applicable.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts maintain full electrical and mechanical compatibility with the LM3478MM. Selection criteria are based on product status and application requirements:

LM3478MM/NOPB and LM3478MMX/NOPB are direct industrial-grade substitutes with active product status and identical electrical specifications. These parts are suitable for standard commercial and industrial applications requiring boost, flyback, or SEPIC topology DC-DC conversion.

LM3478QMM/NOPB and LM3478QMMX/NOPB are automotive-qualified variants meeting AEC-Q100 standards. These parts are required for automotive applications, vehicle power management systems, and designs subject to automotive reliability and qualification requirements.

Packaging format differences (Cut Tape vs. Tape & Reel) do not affect electrical performance and are determined by procurement and assembly process requirements.

Frequently Asked Questions (FAQ)

Q: Can LM3478MM/NOPB replace LM3478MM in existing designs?

A: Yes. LM3478MM/NOPB is electrically and mechanically identical to LM3478MM. The primary difference is product status: LM3478MM is Last Time Buy while LM3478MM/NOPB is Active. Both use the same 8-VSSOP package and support identical topologies, voltage ranges, and switching frequencies.

Q: What is the difference between LM3478MMX/NOPB and LM3478MM/NOPB?

A: Both parts are electrically equivalent with identical electrical specifications, voltage supply range, switching frequency, and operating temperature. The difference is in the device variant designation (MMX vs. MM), which does not affect functional performance or package compatibility.

Q: When should I use the automotive-qualified variants LM3478QMM/NOPB or LM3478QMMX/NOPB?

A: Use automotive-qualified variants when your application requires AEC-Q100 certification or is subject to automotive industry standards. These variants are mandatory for vehicle power management systems and designs requiring automotive-grade reliability qualification.

Q: Are all substitute parts available in the same package?

A: Yes. All substitute parts use the 8-VSSOP package (8-TSSOP, 8-MSOP with 0.118" width, 3.00mm). Packaging format differences (Cut Tape vs. Tape & Reel) refer to supply format only and do not affect the physical package or PCB footprint.

Q: What inventory levels are available for each substitute?

A: LM3478MMX/NOPB has the highest inventory at 47,100 pieces. LM3478QMM/NOPB has 31,400 pieces. LM3478MM/NOPB has 28,200 pieces. LM3478QMMX/NOPB has 17,300 pieces. All parts are in stock as new original components.