FSL518APG Equivalent & Substitute Parts

Part Overview

The FSL518APG is an offline switch flyback converter IC manufactured by onsemi, designed for power management applications requiring isolated DC-DC conversion. This 7-lead PDIP package device operates at 100kHz switching frequency with 17W power capability and includes comprehensive fault protection features. The FSL518APG is classified as obsolete, making identification of equivalent substitute parts essential for design continuity and component sourcing in legacy system maintenance and new designs requiring compatible alternatives.

Substiute Parts

FSL518APG

onsemiIn Stock: 3978FSL518APG Datasheet

Current PartRFQ

FSL518APG

onsemiIn Stock: 3978FSL518APG Datasheet

Parametric EquivalentRFQ

FSL538APG

onsemiIn Stock: 1019FSL538APG Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FSL518APG are identified based on strict parametric equivalence across the following critical selection criteria:

Topology & Electrical Characteristics: Flyback converter topology with 800V breakdown voltage and 100kHz switching frequency form the core functional requirements. All substitutes maintain identical topology and switching frequency specifications.

Power Rating & Thermal Performance: Operating temperature range of -40°C to 125°C (TJ) and fault protection suite (Current Limiting, Over Load, Over Power, Over Temperature, Over Voltage) are mandatory for functional equivalence.

Package & Mechanical Compatibility: 8-DIP (0.300", 7.62mm) with 7 leads and through-hole mounting ensures direct PCB compatibility without layout redesign.

Compliance & Regulatory Status: ROHS3 compliance and EAR99 ECCN classification are maintained across all equivalent parts.

The FSL538APG qualifies as a parametric equivalent based on matching topology, voltage ratings, switching frequency, package configuration, thermal range, and protection features. The primary distinction is increased power rating (25W versus 17W), which represents an upward-compatible substitution.

Parameter Comparison

Engineering Selection Recommendations

Both the FSL518APG and FSL538APG are classified as obsolete products. Selection between these parts is determined by application power requirements and component availability.

The FSL518APG operates at 17W power rating and is suitable for applications within this power envelope. Current inventory shows 3937 pieces in stock.

The FSL538APG provides 25W power capability, offering increased headroom for higher-power applications or designs requiring thermal margin. This part carries 977 pieces in current inventory.

Both parts maintain identical electrical characteristics, package configuration, thermal operating range, and protection features. The FSL538APG represents an upward-compatible substitution for FSL518APG applications where power budget permits. Both parts comply with ROHS3 requirements and carry EAR99 ECCN classification.

Frequently Asked Questions (FAQ)

Q: Can FSL538APG directly replace FSL518APG in existing designs?

A: Yes. The FSL538APG is pin-compatible and functionally equivalent, with identical package, pinout, and electrical interface. The increased 25W power rating does not create incompatibility with 17W designs. No PCB modifications are required.

Q: What is the primary difference between FSL518APG and FSL538APG?

A: The FSL538APG provides 25W power capability compared to the FSL518APG's 17W rating. All other electrical parameters, topology, switching frequency, voltage ratings, protection features, and package specifications are identical.

Q: Are both parts suitable for new designs?

A: Both FSL518APG and FSL538APG are classified as obsolete. Component selection should prioritize availability and supply chain continuity. Current inventory levels are 3937 units (FSL518APG) and 977 units (FSL538APG).

Q: Do package dimensions differ between these parts?

A: No. Both parts use 8-DIP (0.300", 7.62mm) with 7 leads and through-hole mounting. PCB layouts are directly compatible without modification.

Q: Are thermal and protection specifications identical?

A: Yes. Both parts operate across -40°C to 125°C (TJ) and include identical fault protection: Current Limiting, Over Load, Over Power, Over Temperature, and Over Voltage protection. Control features (EN, Soft Start) are also identical.

Q: What compliance certifications apply to both parts?

A: Both FSL518APG and FSL538APG are ROHS3 compliant, REACH unaffected, and classified as EAR99 under ECCN regulations.