TOP221Y Equivalent & Substitute Parts Reference

Part Overview

The TOP221Y is an offline switching converter IC manufactured by Power Integrations, part of the TOPSwitch®-II series. This device integrates a high-voltage power switch with control circuitry for isolated power supply applications supporting Boost, Buck, Flyback, and Forward topologies at 100kHz switching frequency with 12W power rating.

The TOP221Y carries an Obsolete product status. Locating equivalent substitute parts is necessary for design continuity, component availability, and supply chain management. The TOPSwitch®-II family provides multiple power-rated alternatives within the same package and electrical specifications, enabling direct substitution based on application power requirements.

Substiute Parts

TOP221Y

Power IntegrationsIn Stock: 1547TOP221Y Datasheet

Current PartRFQ

TOP221YN

Power IntegrationsIn Stock: 5612TOP221YN Datasheet

Parametric EquivalentRFQ

TOP222YN

Power IntegrationsIn Stock: 56502TOP222YN Datasheet

Parametric EquivalentRFQ

TOP223YN

Power IntegrationsIn Stock: 25262TOP223YN Datasheet

Parametric EquivalentRFQ

TOP224YN

Power IntegrationsIn Stock: 39324TOP224YN Datasheet

Parametric EquivalentRFQ

TOP225YN

Power IntegrationsIn Stock: 8544TOP225YN Datasheet

Parametric EquivalentRFQ

TOP226YN

Power IntegrationsIn Stock: 9926TOP226YN Datasheet

Parametric EquivalentRFQ

TOP227YN

Power IntegrationsIn Stock: 10455TOP227YN Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts within the TOPSwitch®-II family are qualified as electrical and mechanical equivalents when they maintain the following critical parameters:

Fixed Parameters (Must Match for Substitution):

• Package / Case: TO-220-3
• Mounting Type: Through Hole
• Voltage - Breakdown: 700V
• Topology: Boost, Buck, Flyback, Forward
• Frequency - Switching: 100kHz
• Duty Cycle: 67%
• Output Isolation: Isolated
• Internal Switch(s): Yes
• Fault Protection: Current Limiting, Over Temperature
• Operating Temperature: -40°C ~ 150°C (TJ)
• Moisture Sensitivity Level (MSL): 1 (Unlimited)
• REACH Status: REACH Unaffected

Variable Parameter (Determines Power Rating):

• Power (Watts): Varies by part number (12W to 150W)

The TOP221Y can be substituted with any TOPSwitch®-II variant maintaining identical electrical and mechanical specifications. Substitution is valid when the replacement part's power rating meets or exceeds the application requirement. All substitute parts listed are manufactured by Power Integrations and belong to the same TOPSwitch®-II series.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Same Power Rating):

TOP221YN is the direct equivalent to TOP221Y, maintaining identical 12W power specification. TOP221YN carries RoHS Compliant status and Not For New Designs product status, providing improved environmental compliance over the obsolete TOP221Y. Packaging differs (Tube vs. Bulk), but electrical and mechanical specifications remain identical.

For Power-Scaled Substitution:

When application power requirements exceed 12W, substitute parts from the TOPSwitch®-II family provide higher power ratings while maintaining all other electrical and mechanical parameters. Selection depends on actual power demand:

• 25W requirement: TOP222YN
• 50W requirement: TOP223YN
• 75W requirement: TOP224YN
• 100W requirement: TOP225YN
• 125W requirement: TOP226YN
• 150W requirement: TOP227YN

All substitute parts carry RoHS Compliant status and Not For New Designs product status. All maintain TO-220-3 package compatibility and through-hole mounting.

Compliance Considerations:

The original TOP221Y is RoHS non-compliant. All listed substitutes (TOP221YN through TOP227YN) are RoHS Compliant. All parts maintain REACH Unaffected status. Selection of RoHS-compliant alternatives aligns with current environmental regulations and supply chain requirements.

Frequently Asked Questions (FAQ)

Q: Can TOP221YN directly replace TOP221Y in existing designs?

A: Yes. TOP221YN maintains identical electrical specifications (12W power, 700V breakdown, 100kHz switching, 67% duty cycle, isolated output, TO-220-3 package, through-hole mounting). The primary differences are product status (Not For New Designs vs. Obsolete) and RoHS compliance (Compliant vs. non-compliant). Packaging format differs (Tube vs. Bulk) but does not affect electrical performance.

Q: What determines whether a higher-power TOPSwitch®-II part can substitute for TOP221Y?

A: Substitution is valid when all electrical and mechanical parameters match: 700V breakdown voltage, 100kHz switching frequency, 67% duty cycle, Boost/Buck/Flyback/Forward topology support, isolated output, current limiting and over-temperature protection, -40°C to 150°C operating range, and TO-220-3 through-hole package. Power rating is the only variable parameter. Higher-rated parts (TOP222YN through TOP227YN) are compatible substitutes for applications requiring greater power capacity.

Q: Are all substitute parts in the same package?

A: Yes. All listed substitutes use TO-220-3 package with through-hole mounting. Packaging format (Tube vs. Bulk) differs between TOP221Y and the substitute parts, but the component package itself remains identical, ensuring mechanical compatibility with existing PCB layouts and thermal management solutions.

Q: What is the significance of "Not For New Designs" status on substitute parts?

A: "Not For New Designs" indicates the part is available for existing design support and replacement applications but is not recommended for new product development. This status reflects the maturity of the TOPSwitch®-II series. For replacement and repair of existing TOP221Y designs, these parts provide full functional equivalence.

Q: Why do substitute parts have higher power ratings?

A: The TOPSwitch®-II series offers multiple power-rated variants within identical electrical and mechanical specifications. Higher-rated parts (TOP222YN through TOP227YN) provide design flexibility for applications requiring increased power capacity while maintaining compatibility with the same control architecture, package, and protection features.

Q: Is RoHS compliance important for TOP221Y replacement?

A: RoHS compliance status depends on application requirements and regional regulations. All substitute parts listed (TOP221YN through TOP227YN) are RoHS Compliant, providing alignment with current environmental standards. The original TOP221Y is RoHS non-compliant. Selection of compliant alternatives supports regulatory compliance and supply chain continuity.