LM3477MMX Buck-Boost Regulator Controller IC Equivalent & Substitute Parts

Part Overview

The LM3477MMX is a buck-boost regulator controller IC manufactured by Texas Instruments, designed for step-down DC-DC conversion applications. This device operates as a transistor driver with positive output configuration and supports both buck and buck-boost topologies. The main part is currently in Last Time Buy status, making identification of equivalent and substitute parts essential for design continuity and procurement planning. Substitute parts maintain identical electrical and mechanical specifications while offering different packaging options or active product status.

Substiute Parts

LM3477MMX

Texas InstrumentsIn Stock: 2317LM3477MMX Datasheet

Current PartRFQ

LM3477MMX/NOPB

National SemiconductorIn Stock: 4168LM3477MMX/NOPB Datasheet

DirectRFQ

LM3477AMM/NOPB

National SemiconductorIn Stock: 7387LM3477AMM/NOPB Datasheet

Parametric EquivalentRFQ

LM3477AMMX/NOPB

National SemiconductorIn Stock: 3344LM3477AMMX/NOPB Datasheet

Parametric EquivalentRFQ

LM3477MM/NOPB

Texas InstrumentsIn Stock: 5628LM3477MM/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the LM3477MMX are identified based on matching the following critical parameters: output type (transistor driver), function (step-down), output configuration (positive), topology (buck, buck-boost), number of outputs (1), output phases (1), supply voltage range (2.97V ~ 35V), switching frequency (500kHz), duty cycle maximum (93%), operating temperature range (-40°C ~ 125°C), package type (8-TSSOP, 8-MSOP), and supplier device package (8-VSSOP).

Substitute parts are grouped into two categories:

Direct Manufacturer Part Number: LM3477MMX/NOPB maintains identical specifications with different packaging designation and active product status.

Parametric Equivalents: LM3477AMM/NOPB, LM3477AMMX/NOPB, and LM3477MM/NOPB share all electrical and mechanical parameters with the main part while differing in packaging format (bulk or tape & reel) and product status (active).

Parameter Comparison

Engineering Selection Recommendations

For applications currently using LM3477MMX, substitute selection depends on product status requirements and compliance certifications:

LM3477MM/NOPB is the primary substitute, offering active product status from Texas Instruments with identical RoHS3 compliance, moisture sensitivity level, and REACH status. This part maintains tape & reel packaging consistent with the original specification.

LM3477MMX/NOPB provides direct equivalence with active product status from National Semiconductor. This option is suitable when National Semiconductor sourcing is preferred or when inventory availability from alternative suppliers is required.

LM3477AMM/NOPB and LM3477AMMX/NOPB are parametric equivalents with active product status. LM3477AMMX/NOPB is available in bulk packaging, suitable for applications where tape & reel format is not required. These National Semiconductor variants maintain all electrical specifications and export classifications.

All substitute parts share identical electrical performance characteristics, package dimensions, and thermal operating ranges. Selection among active alternatives should be based on packaging format requirements, supplier availability, and compliance documentation needs.

Frequently Asked Questions (FAQ)

Q: Can LM3477MM/NOPB directly replace LM3477MMX in existing designs?

A: Yes. LM3477MM/NOPB maintains identical electrical specifications, package type (8-TSSOP, 8-MSOP), supplier device package (8-VSSOP), supply voltage range (2.97V ~ 35V), switching frequency (500kHz), duty cycle (93%), and operating temperature range (-40°C ~ 125°C). No circuit modifications are required.

Q: What is the difference between LM3477MMX/NOPB and LM3477AMMX/NOPB?

A: Both parts are parametric equivalents with identical electrical and mechanical specifications. The primary difference is packaging format: LM3477MMX/NOPB packaging is not specified, while LM3477AMMX/NOPB is supplied in bulk format. Manufacturer differs (National Semiconductor for both), and product status is active for both.

Q: Are there compliance differences between the main part and substitute options?

A: LM3477MMX and LM3477MM/NOPB both carry ROHS3 compliance, MSL 1 (Unlimited), and REACH Unaffected status. LM3477MMX/NOPB, LM3477AMM/NOPB, and LM3477AMMX/NOPB do not specify these compliance attributes in available documentation. All parts share identical ECCN (EAR99) and HTSUS (8542.39.0001) classifications.

Q: Why is LM3477MMX marked as Last Time Buy?

A: Last Time Buy status indicates the manufacturer is discontinuing this specific part number variant. Substitute parts with active status (LM3477MM/NOPB, LM3477MMX/NOPB, LM3477AMM/NOPB, LM3477AMMX/NOPB) ensure long-term design support and continued availability.

Q: Do all substitute parts support the same topology and output configuration?

A: Yes. All substitute parts support buck and buck-boost topologies with positive output configuration, single output, and single output phase. Transistor driver output type and enable control features are identical across all variants.

Q: What packaging options are available among the substitute parts?

A: LM3477MM/NOPB is supplied in tape & reel (TR) format. LM3477AMMX/NOPB is supplied in bulk format. LM3477MMX/NOPB and LM3477AMM/NOPB have unspecified packaging designations. All parts use identical 8-TSSOP, 8-MSOP (0.118", 3.00mm width) package type and 8-VSSOP supplier device package.