TOP221PN Equivalent & Substitute Parts

Part Overview

The TOP221PN is an offline switch IC manufactured by Power Integrations, designed for isolated power conversion applications supporting Boost, Buck, Flyback, and Forward topologies. This device operates at 100kHz switching frequency with 9W power handling capability and is housed in an 8-DIP package for through-hole mounting.

The TOP221PN carries a "Not For New Designs" product status, indicating that Power Integrations has discontinued active development for this component. Organizations requiring this functionality for new or ongoing projects must evaluate equivalent and substitute parts that maintain compatibility with existing designs or provide enhanced performance characteristics.

Substiute Parts

TOP221PN

Power IntegrationsIn Stock: 17224TOP221PN Datasheet

Current PartRFQ

TNY285PG

Power IntegrationsIn Stock: 40733TNY285PG Datasheet

SimilarRFQ

TOP242PN

Power IntegrationsIn Stock: 1754TOP242PN Datasheet

SimilarRFQ

TOP222PN

Power IntegrationsIn Stock: 17336TOP222PN Datasheet

Parametric EquivalentRFQ

TOP223PN

Power IntegrationsIn Stock: 19404TOP223PN Datasheet

Parametric EquivalentRFQ

TOP224PN

Power IntegrationsIn Stock: 18350TOP224PN Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TOP221PN are classified based on the following critical parameters that determine functional compatibility:

Topology Compatibility: The TOP221PN supports multiple topologies (Boost, Buck, Flyback, Forward). Substitutes must support at least the same topologies required by the application circuit.

Package and Mounting: All substitute parts maintain the 8-DIP through-hole package format, ensuring direct PCB compatibility without layout modifications.

Voltage Rating: The 700V breakdown voltage specification is maintained across parametric equivalents within the TOPSwitch®-II series to ensure safe operation in offline converter applications.

Switching Frequency and Duty Cycle: The 100kHz switching frequency and 67% duty cycle are core design parameters. Substitutes may operate at different frequencies if the application topology permits frequency variation.

Power Rating: Substitute parts are grouped by power handling capability (9W, 15W, 25W, 30W). Selection depends on the actual power requirements of the target application.

Fault Protection Features: Current limiting and over-temperature protection are standard across all substitutes. Enhanced protection features (over-voltage, short-circuit) are available in alternative series.

Product Status and Compliance: RoHS compliance and REACH status are consistent across all listed substitutes, supporting regulatory requirements for new designs.

Parameter Comparison

Engineering Selection Recommendations

Parametric Equivalents within TOPSwitch®-II Series:

The TOP222PN, TOP223PN, and TOP224PN are parametric equivalents of the TOP221PN, maintaining identical topology support, switching frequency, duty cycle, and voltage ratings. These parts differ only in power rating (15W, 25W, and 30W respectively). Selection among these parts depends on the actual power requirements of the application. All three carry "Not For New Designs" status, consistent with the TOP221PN.

Topology-Specific Substitutes:

The TOP242PN operates exclusively in Flyback topology with variable frequency control (66kHz ~ 132kHz) and higher power rating (15W). This substitute is appropriate only for applications requiring Flyback topology. The TOP242PN also carries "Not For New Designs" status.

The TNY285PG represents an alternative from the TinySwitch®-4 series, supporting only Flyback topology with enhanced fault protection features (over-voltage and short-circuit protection). Critically, the TNY285PG maintains "Active" product status, making it suitable for new design implementations. The TNY285PG operates at a higher switching frequency range (124kHz ~ 140kHz) and provides 8.5W power handling.

Compliance and Regulatory Considerations:

All listed substitutes maintain RoHS compliance and REACH unaffected status, satisfying regulatory requirements for electronic component procurement. Moisture sensitivity level (MSL) is 1 (Unlimited) across all parts, indicating no special storage or handling requirements.

Product Status Impact:

Organizations developing new products should prioritize the TNY285PG due to its Active product status. Existing designs using TOP221PN may continue with parametric equivalents (TOP222PN, TOP223PN, TOP224PN) for maintenance and repair purposes, provided power requirements remain within the specified range.

Frequently Asked Questions (FAQ)

Q: Can TOP222PN, TOP223PN, or TOP224PN be used as direct replacements for TOP221PN?

A: TOP222PN, TOP223PN, and TOP224PN are parametric equivalents sharing identical topology support, switching frequency, duty cycle, voltage rating, and package format. Direct substitution is possible if the application power requirement does not exceed the original TOP221PN specification of 9W. If higher power handling is required, TOP222PN (15W), TOP223PN (25W), or TOP224PN (30W) provide increased capacity within the same package and electrical characteristics.

Q: What is the difference between TOP242PN and TOP221PN?

A: TOP242PN differs in topology support (Flyback only versus multi-topology), switching frequency range (66kHz ~ 132kHz versus fixed 100kHz), and power rating (15W versus 9W). TOP242PN is suitable only for applications requiring Flyback topology. Both parts carry "Not For New Designs" status.

Q: Why is TNY285PG recommended for new designs?

A: TNY285PG maintains Active product status, indicating ongoing manufacturer support and availability. This part is appropriate for new product development. TNY285PG operates in Flyback topology only and includes enhanced fault protection (over-voltage and short-circuit detection) compared to TOP221PN. The switching frequency range (124kHz ~ 140kHz) differs from TOP221PN's fixed 100kHz.

Q: Are all substitute parts RoHS compliant?

A: All listed substitute parts (TOP222PN, TOP223PN, TOP224PN, TOP242PN, TNY285PG) are RoHS compliant and REACH unaffected, meeting regulatory requirements for electronic component procurement in regulated markets.

Q: Can TNY285PG replace TOP221PN in multi-topology applications?

A: No. TNY285PG supports Flyback topology only, while TOP221PN supports Boost, Buck, Flyback, and Forward topologies. TNY285PG is suitable only for applications requiring Flyback topology. For multi-topology support, use TOP222PN, TOP223PN, or TOP224PN.

Q: What is the package compatibility between TOP221PN and substitute parts?

A: All substitute parts use the 8-DIP (0.300", 7.62mm) through-hole package, ensuring direct PCB compatibility without layout modifications or rework.

Q: How do switching frequency differences affect substitution?

A: TOP221PN operates at fixed 100kHz. TOP242PN operates at 66kHz ~ 132kHz with frequency control, and TNY285PG operates at 124kHz ~ 140kHz. Frequency variation affects transformer design, EMI characteristics, and component selection. Substitution with different frequency specifications requires circuit validation to ensure performance meets application requirements.

Q: What additional fault protection does TNY285PG provide?

A: TNY285PG includes Current Limiting, Open Loop, Over Temperature, Over Voltage, and Short Circuit protection. TOP221PN provides Current Limiting and Over Temperature protection only. Enhanced protection in TNY285PG may reduce design complexity for applications requiring comprehensive fault handling.