TOP250FN Equivalent & Substitute Parts

Part Overview

The TOP250FN is an offline flyback converter IC from Power Integrations' TOPSwitch®-GX series, designed for isolated power supply applications. It integrates a 700V breakdown voltage switch with frequency control and comprehensive fault protection in a TO-262-7C through-hole package. The device operates at 66kHz to 132kHz switching frequency with 290W power capability and is rated for -40°C to 150°C junction temperature operation.

The TOP250FN is classified as obsolete. Identifying equivalent substitute parts is necessary to support legacy system maintenance, design updates, and procurement continuity when original inventory becomes unavailable.

Substiute Parts

TOP250FN

Power IntegrationsIn Stock: 25240TOP250FN Datasheet

Current PartRFQ

TOP271KG-TL

Power IntegrationsIn Stock: 2283TOP271KG-TL Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the TOP250FN is evaluated based on the following critical parameters that define functional equivalence in offline flyback converter applications:

Topology & Isolation: Both the main part and substitute must operate as isolated flyback converters with internal switching capability.

Voltage Rating: Breakdown voltage must be sufficient for the application. The TOP250FN operates at 700V; substitute parts must meet or exceed this specification.

Switching Frequency: Operating frequency range must overlap or be compatible with 66kHz to 132kHz operation.

Power Capability: The substitute must support the required power level. The TOP250FN is rated for 290W.

Fault Protection: Equivalent protection features (current limiting, over temperature, over voltage) must be present.

Compliance & Status: RoHS compliance and regulatory certifications must be maintained.

Package Compatibility: Physical package type determines board-level integration feasibility. The TOP250FN uses through-hole TO-262-7C packaging.

The TOP271KG-TL is identified as a substitute based on shared topology, isolation architecture, frequency control capability, and compliance certifications. However, differences in power rating, package type, and duty cycle must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The TOP250FN is obsolete, while the TOP271KG-TL is active. Active product status ensures continued availability, technical support, and manufacturing consistency.

Compliance & Certifications: Both parts maintain RoHS compliance and REACH unaffected status, satisfying regulatory requirements for equivalent applications.

Power Rating Differential: The TOP271KG-TL is rated for 102W, significantly lower than the TOP250FN's 290W capability. Substitution is applicable only to applications requiring ≤102W output power.

Package Type Change: The TOP250FN uses through-hole TO-262-7C packaging, while the TOP271KG-TL uses surface-mount 12-ESOP packaging. Board redesign is required for substitution.

Voltage & Frequency Compatibility: The TOP271KG-TL's 725V breakdown voltage exceeds the TOP250FN's 700V requirement. Both support 66kHz and 132kHz switching frequencies.

Enhanced Protection: The TOP271KG-TL includes over-load and short-circuit protection in addition to the TOP250FN's protection features, providing improved fault handling.

Substitution of TOP250FN with TOP271KG-TL is valid for isolated flyback applications operating at ≤102W power levels, with board-level modifications to accommodate surface-mount packaging.

Frequently Asked Questions (FAQ)

Q: Can the TOP271KG-TL directly replace the TOP250FN without board modifications?

A: No. The TOP250FN uses through-hole TO-262-7C packaging, while the TOP271KG-TL uses surface-mount 12-ESOP packaging. PCB layout and footprint changes are required.

Q: What is the primary limitation when substituting TOP250FN with TOP271KG-TL?

A: Power rating. The TOP271KG-TL is rated for 102W maximum output, compared to the TOP250FN's 290W. Substitution is limited to applications requiring ≤102W power delivery.

Q: Are both parts compatible with the same switching frequency range?

A: Both parts support 66kHz and 132kHz switching frequencies. The TOP250FN specifies a continuous range (66kHz ~ 132kHz), while the TOP271KG-TL specifies discrete frequencies (66kHz, 132kHz).

Q: Does the TOP271KG-TL provide equivalent fault protection?

A: The TOP271KG-TL provides enhanced protection, including current limiting, over-load, over-temperature, over-voltage, and short-circuit protection. The TOP250FN includes current limiting, over-temperature, and over-voltage protection.

Q: What is the voltage rating difference between these parts?

A: The TOP250FN has a 700V breakdown voltage, while the TOP271KG-TL has a 725V breakdown voltage. The TOP271KG-TL's higher rating is compatible with TOP250FN applications.

Q: Is the TOP271KG-TL suitable for legacy system maintenance?

A: The TOP271KG-TL is active and in stock, making it suitable for legacy support. However, power rating and package type must be verified against original design specifications before implementation.

Q: What duty cycle difference exists between these parts?

A: The TOP250FN operates at 66.8% duty cycle, while the TOP271KG-TL operates at 78% duty cycle. This difference reflects different internal design architectures and may affect transformer design requirements.