LC5555LD LED Driver IC Equivalent & Substitute Parts

Part Overview

The LC5555LD is an AC DC offline switcher LED driver IC manufactured by Sanken Electric USA Inc., designed for step-down (buck) topology applications with internal switching capability. This device operates across a supply voltage range up to 18V and is housed in an 8-DIP through-hole package with 7 leads. The LC5555LD is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility as AC DC offline switcher LED drivers while accommodating different package types and electrical specifications.

Substiute Parts

LC5555LD

Sanken Electric USA Inc.In Stock: 882LC5555LD Datasheet

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AP1685MTR-G1

Diodes IncorporatedIn Stock: 40399AP1685MTR-G1 Datasheet

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LNK403LG

Power IntegrationsIn Stock: 5218LNK403LG Datasheet

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MP4021GS-LF

Monolithic Power Systems Inc.In Stock: 1074MP4021GS-LF Datasheet

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MP4050AGJ-P

Monolithic Power Systems Inc.In Stock: 787MP4050AGJ-P Datasheet

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MP4050AGS

Monolithic Power SystemsIn Stock: 872MP4050AGS Datasheet

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MP4050AGS-Z

Monolithic Power Systems Inc.In Stock: 3895MP4050AGS-Z Datasheet

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MP4050GS

Monolithic Power Systems Inc.In Stock: 1336MP4050GS Datasheet

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MP4054AGJ-Z

Monolithic Power SystemsIn Stock: 4602MP4054AGJ-Z Datasheet

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MXHV9910BTR

IXYS Integrated Circuits DivisionIn Stock: 2324MXHV9910BTR Datasheet

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RT8497AGS

Richtek USA Inc.In Stock: 25338RT8497AGS Datasheet

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RT8497BGS

Richtek USA Inc.In Stock: 2081RT8497BGS Datasheet

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TPS92010D

Texas InstrumentsIn Stock: 1480TPS92010D Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the LC5555LD is determined by the following critical parameters: AC DC offline switcher topology, step-down (buck) configuration, single output, internal switching capability, and RoHS compliance. Substitute parts are grouped into two functional categories based on topology and electrical characteristics:

Category 1: Step-Down (Buck) Topology with Internal Switch Parts maintaining step-down buck topology with integrated switching: AP1685MTR-G1, MP4050AGJ-P, MP4050AGS, MP4050AGS-Z, MP4050GS, MXHV9910BTR, and RT8497AGS. These parts preserve the core buck converter architecture and internal switch requirement of the LC5555LD.

Category 2: Alternative Topologies (Flyback) Parts using alternative topologies for LED driver applications: LNK403LG (flyback with triac dimming) and MP4021GS-LF (flyback without internal switch). These represent functional alternatives where system design permits topology variation.

Category 3: Multi-Topology Converters Parts supporting both step-down and step-up configurations: MP4054AGJ-Z. This part extends functionality beyond the LC5555LD's buck-only topology.

Substitution logic prioritizes matching the AC DC offline switcher classification, single-output requirement, and RoHS compliance status across all candidates.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Active Status, Buck Topology, Internal Switch): AP1685MTR-G1 is the primary substitute for the LC5555LD when transitioning from through-hole to surface-mount assembly. This part maintains step-down buck topology with internal switching, operates within compatible voltage ranges (8V-25V), and holds active product status with ROHS3 compliance. The 8-SOIC package requires PCB layout modification from the original 8-DIP footprint.

For High-Temperature Applications: LNK403LG provides extended operating temperature range (-40°C to 150°C) and maintains AC DC offline switcher classification. However, this part uses flyback topology rather than buck topology, requiring circuit redesign. The through-hole 7-SSIP package accommodates board-level integration similar to the LC5555LD.

For Low-Voltage Buck Applications (4.1V-5V): MP4050AGS-Z and MP4050AGJ-P are active substitutes for applications within the 4.1V-5V supply range. Both maintain step-down buck topology with internal switching and RoHS3 compliance. MP4050AGS-Z uses 8-SOIC surface-mount packaging, while MP4050AGJ-P offers SOT-23-5 compact form factor with automotive-grade qualification.

For AC Line-Powered Applications (85VAC-265VAC): MP4050GS is designed for direct AC line input applications, maintaining step-down buck topology and RoHS3 compliance with 8-SOIC surface-mount packaging.

For Extended Voltage Range (8V-450V): MXHV9910BTR accommodates wide input voltage ranges suitable for diverse power supply architectures. This part operates as an AC DC offline switcher with step-down buck topology but lacks internal switching capability, requiring external switch implementation.

All recommended substitutes maintain RoHS compliance status and single-output LED driver functionality. Product status (active vs. obsolete) should be verified against current supply chain availability.

Frequently Asked Questions (FAQ)

Q: Can the LC5555LD be directly replaced with a surface-mount package substitute? A: Yes, surface-mount substitutes such as AP1685MTR-G1, MP4050AGS-Z, and RT8497AGS provide functional equivalence but require PCB redesign to accommodate different package footprints. The original 8-DIP through-hole package must be replaced with 8-SOIC or alternative surface-mount patterns.

Q: What is the primary difference between buck and flyback topology substitutes? A: Buck topology (step-down) directly reduces input voltage to output voltage using a series switch and inductor. Flyback topology uses transformer isolation and energy storage in the transformer core. LNK403LG and MP4021GS-LF employ flyback topology, requiring different circuit design and component selection compared to the LC5555LD's buck architecture.

Q: Are all substitute parts RoHS compliant? A: All listed substitute parts maintain RoHS compliance (RoHS Compliant or ROHS3 Compliant status). This ensures compatibility with environmental and regulatory requirements equivalent to the LC5555LD.

Q: Which substitute offers the widest operating temperature range? A: LNK403LG provides the widest operating temperature range (-40°C to 150°C junction temperature), exceeding the LC5555LD's -55°C to 125°C ambient temperature range. This part is suitable for high-temperature environment applications.

Q: What is the significance of "internal switch" specification? A: Internal switch capability indicates the IC contains integrated power switching circuitry, eliminating the need for external discrete switching transistors. The LC5555LD, AP1685MTR-G1, MP4050 series, and RT8497AGS include internal switches. MXHV9910BTR and MP4054AGJ-Z lack internal switches, requiring external switch implementation and increasing circuit complexity.

Q: Can MP4050 series parts substitute for each other? A: MP4050AGJ-P, MP4050AGS, MP4050AGS-Z, and MP4050GS share the same base product number (MP4050) and maintain step-down buck topology with internal switching. However, they differ in voltage supply ranges and packaging. MP4050AGJ-P and MP4050AGS operate at 4.1V-5V, while MP4050GS operates at 85VAC-265VAC. Verify voltage compatibility before substitution.

Q: What packaging considerations apply when selecting a substitute? A: The LC5555LD uses 8-DIP through-hole packaging. Surface-mount substitutes (8-SOIC, SOT-23-5, SOT-23-8) require PCB layout redesign and different assembly processes. Through-hole alternatives (LNK403LG in 7-SSIP) maintain similar board integration but may require footprint adaptation due to different lead counts and spacing.

Q: Is RT8497AGS suitable for new designs despite obsolete status? A: RT8497AGS is classified as obsolete, indicating discontinued manufacturing. While functionally equivalent to the LC5555LD as a step-down buck AC DC offline switcher, new designs should prioritize active-status alternatives such as AP1685MTR-G1 or MP4050 series to ensure long-term supply chain availability and support.