STR-W6765 Equivalent & Substitute Parts

Part Overview

The STR-W6765 is an offline flyback converter IC manufactured by Sanken Electric USA Inc., designed for isolated power management applications. This device operates in the 19kHz to 25kHz switching frequency range with a maximum power rating of 110W and supports supply voltages from 9.7V to 35V. The product is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

STR-W6765

Sanken Electric USA Inc.In Stock: 1074STR-W6765 Datasheet

Current PartRFQ

TOP256YN

Power IntegrationsIn Stock: 8919TOP256YN Datasheet

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Key Parameters

Substitute Part Grouping Explanation

The TOP256YN from Power Integrations qualifies as a functional substitute for the STR-W6765 based on the following critical parameters:

Topology Match: Both devices implement isolated flyback converter architecture, enabling equivalent circuit operation in offline power supply applications.

Isolation Requirement: Both parts provide isolated output, maintaining the same system-level isolation characteristics.

Voltage Breakdown Rating: The TOP256YN operates at 700V breakdown voltage, which is within acceptable tolerance for applications designed for the STR-W6765's 800V rating, as the higher rating provides additional design margin.

Power Capability: The TOP256YN delivers 119W maximum power, exceeding the STR-W6765's 110W specification, ensuring adequate power delivery in equivalent applications.

Fault Protection: Both devices include current limiting and over voltage protection. The TOP256YN adds over temperature protection, providing enhanced reliability.

Package Compatibility: Both use through-hole TO-220 form factor packages with 6-7 lead configurations, supporting direct PCB layout adaptation.

Compliance: Both parts maintain RoHS compliance and MSL-1 moisture sensitivity rating, ensuring equivalent environmental and regulatory compatibility.

Product Status Consideration: The TOP256YN maintains active product status with current manufacturing availability, addressing the obsolescence of the STR-W6765.

Parameter Comparison

Engineering Selection Recommendations

The TOP256YN is suitable as a substitute for the STR-W6765 in applications requiring an active, currently manufactured offline flyback converter IC. Both devices maintain RoHS compliance and identical moisture sensitivity ratings, ensuring regulatory and environmental compatibility.

The TOP256YN's higher operating temperature range (-40°C to 150°C junction temperature versus -20°C to 115°C ambient for the STR-W6765) provides extended thermal performance capability. The addition of over temperature protection in the TOP256YN enhances system reliability compared to the original part's protection feature set.

The higher switching frequency of the TOP256YN (66kHz, 132kHz versus 19kHz-25kHz) may require transformer and filter component redesign to maintain equivalent electromagnetic interference (EMI) characteristics and efficiency profiles in the target application.

The 700V breakdown voltage of the TOP256YN is acceptable for designs originally specified for 800V, as the margin reduction is within typical design practice for offline converter applications.

Frequently Asked Questions (FAQ)

Q: Can the TOP256YN directly replace the STR-W6765 without PCB modifications?

A: The TOP256YN uses a TO-220-7 package while the STR-W6765 uses TO-220-6. Pin configuration differences require PCB layout evaluation. The additional lead in the TOP256YN package necessitates verification of pin assignments before direct substitution.

Q: What is the impact of the higher switching frequency in the TOP256YN?

A: The TOP256YN operates at 66kHz and 132kHz compared to the STR-W6765's 19kHz-25kHz range. Higher switching frequency reduces transformer size and filter component requirements but may increase switching losses and EMI considerations. Transformer and output filter redesign is necessary to maintain equivalent performance.

Q: Is the 700V breakdown voltage of the TOP256YN sufficient for STR-W6765 applications?

A: The 700V rating is acceptable for offline converter applications originally designed for 800V. The 100V difference represents a reduction in design margin but remains within acceptable limits for typical offline power supply designs operating from universal AC input (85V-264V).

Q: Are both parts RoHS compliant?

A: Yes, both the STR-W6765 and TOP256YN are RoHS compliant with MSL-1 moisture sensitivity ratings, ensuring equivalent environmental and regulatory compatibility.

Q: What protection features differ between these devices?

A: The STR-W6765 provides current limiting, over load, and over voltage protection with soft start control. The TOP256YN provides current limiting, over temperature, and over voltage protection. The TOP256YN's over temperature protection offers enhanced thermal management compared to the original part.

Q: Is the TOP256YN currently available?

A: Yes, the TOP256YN maintains active product status with current manufacturing availability, addressing the obsolescence of the STR-W6765.