TOP223GN Equivalent & Substitute Parts

Part Overview

The TOP223GN is an offline switching converter IC from Power Integrations' TOPSwitch®-II series, designed for isolated power supply applications. This 8-SMD surface mount device supports multiple topologies including Boost, Buck, Flyback, and Forward configurations with a 25W power rating and 100kHz switching frequency. The part is discontinued at DiGi Electronics, making equivalent and substitute parts essential for ongoing production and design continuity. Alternative components must maintain electrical compatibility across voltage ratings, power handling, isolation characteristics, and thermal performance to ensure direct substitution in existing designs.

Substiute Parts

TOP223GN

Power IntegrationsIn Stock: 9662TOP223GN Datasheet

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TOP223GN-TL

Power IntegrationsIn Stock: 4469TOP223GN-TL Datasheet

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TOP243GN-TL

Power IntegrationsIn Stock: 18359TOP243GN-TL Datasheet

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FSQ0370RLA

Fairchild SemiconductorIn Stock: 1650FSQ0370RLA Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the TOP223GN is determined by strict alignment of the following critical parameters:

Primary Substitution Criteria:

• Voltage breakdown rating (700V minimum)
• Power handling capability (25W nominal)
• Switching frequency (100kHz or compatible range)
• Output isolation (Isolated topology required)
• Internal integrated switch (Yes)
• Fault protection features (Current Limiting, Over Temperature minimum)
• Operating temperature range (-40°C to 150°C or compatible)
• Surface mount 8-SMD package compatibility
• RoHS compliance status

Substitute Parts Identified:

1. TOP223GN-TL (Power Integrations TOPSwitch®-II): Identical electrical specifications with Tape & Reel packaging. Differs only in packaging format and product status (Not For New Designs).

2. TOP243GN-TL (Power Integrations TOPSwitch®-GX): Maintains 700V breakdown, 25W power, isolated output, and 8-SMD package. Topology limited to Flyback. Switching frequency range 66kHz–132kHz encompasses the 100kHz operation point. Includes additional Over Voltage protection and Frequency Control features.

3. FSQ0370RLA (Fairchild Semiconductor FPS™): Meets 700V breakdown, 27W power capability, isolated Flyback topology, 100kHz switching frequency, and 8-SMD package. Includes enhanced fault protection (Over Load, Over Voltage in addition to Current Limiting and Over Temperature). Operating temperature limited to -40°C to 85°C (TA). Active product status.

Parameter Comparison

Engineering Selection Recommendations

TOP223GN-TL (Power Integrations): This substitute provides identical electrical and thermal specifications to the TOP223GN with only packaging format differentiation (Tape & Reel versus standard packaging). Both parts are RoHS compliant and share the same TOPSwitch®-II series architecture. Selection of TOP223GN-TL is appropriate for designs requiring exact electrical equivalence. However, product status is "Not For New Designs," indicating limited long-term availability.

TOP243GN-TL (Power Integrations): This part maintains critical electrical parameters including 700V breakdown voltage, 25W power rating, isolated output, and 8-SMD surface mount package. The switching frequency range of 66kHz–132kHz encompasses the 100kHz operation point of the TOP223GN. Topology is limited to Flyback, restricting use to designs originally specified for Flyback operation only. Enhanced fault protection includes Over Voltage detection. RoHS compliant. Product status is "Not For New Designs."

FSQ0370RLA (Fairchild Semiconductor): This part meets core electrical requirements with 700V breakdown, 27W power capability, isolated Flyback topology, and 100kHz switching frequency in an 8-SMD package. Enhanced fault protection includes Over Load and Over Voltage features beyond the TOP223GN baseline. Critical limitation: operating temperature range is -40°C to 85°C (TA), which is narrower than the TOP223GN's -40°C to 150°C (TJ) specification. This part carries Active product status, providing superior long-term availability. RoHS status is not specified in available documentation.

For applications requiring multi-topology support (Boost, Buck, Flyback, Forward), only TOP223GN-TL provides full equivalence. For Flyback-only designs with extended temperature operation, TOP243GN-TL is suitable. For new designs prioritizing long-term component availability, FSQ0370RLA is the recommended choice, provided operating temperature requirements do not exceed 85°C ambient.

Frequently Asked Questions (FAQ)

Q: Can TOP223GN-TL be used as a direct replacement for TOP223GN?

A: Yes. TOP223GN-TL is electrically and thermally identical to TOP223GN. The only difference is packaging format (Tape & Reel versus standard). Both support Boost, Buck, Flyback, and Forward topologies with identical 700V breakdown, 25W power, 100kHz switching frequency, and -40°C to 150°C operating temperature range. Both are RoHS compliant.

Q: What is the key limitation of TOP243GN-TL as a substitute?

A: TOP243GN-TL supports Flyback topology only, whereas TOP223GN supports Boost, Buck, Flyback, and Forward topologies. If the original design uses Boost, Buck, or Forward topologies, TOP243GN-TL is not suitable. For Flyback-only applications, TOP243GN-TL is compatible with identical 700V breakdown, 25W power, and -40°C to 150°C operating temperature.

Q: Why is FSQ0370RLA's operating temperature range different?

A: FSQ0370RLA specifies -40°C to 85°C ambient temperature (TA), whereas TOP223GN specifies -40°C to 150°C junction temperature (TJ). These are different measurement points. FSQ0370RLA is suitable only for applications where ambient temperature does not exceed 85°C. Designs requiring higher temperature operation must use TOP223GN-TL or TOP243GN-TL.

Q: Are all substitute parts RoHS compliant?

A: TOP223GN-TL and TOP243GN-TL are explicitly RoHS compliant. FSQ0370RLA's RoHS status is not specified in the provided documentation and must be verified with the manufacturer before use in RoHS-restricted applications.

Q: Which substitute has the best long-term availability?

A: FSQ0370RLA carries Active product status, indicating ongoing manufacturing and distribution. TOP223GN-TL and TOP243GN-TL are both marked "Not For New Designs," indicating limited future availability. For new designs requiring extended component lifecycle, FSQ0370RLA is the preferred choice, subject to topology and temperature requirements.

Q: Can FSQ0370RLA replace TOP223GN in multi-topology designs?

A: No. FSQ0370RLA supports Flyback topology only. TOP223GN supports Boost, Buck, Flyback, and Forward topologies. FSQ0370RLA is suitable only for designs originally specified for Flyback operation.

Q: What is the significance of the 8-SMD package specification?

A: All substitute parts use 8-SMD surface mount packages with Gull Wing leads, ensuring PCB footprint compatibility with TOP223GN. TOP243GN-TL specifies 7 leads within the 8-SMD package, which may require verification of pinout compatibility in specific applications.

Q: How do fault protection features differ among substitutes?

A: TOP223GN and TOP223GN-TL provide Current Limiting and Over Temperature protection. TOP243GN-TL adds Over Voltage protection. FSQ0370RLA provides the most comprehensive protection with Current Limiting, Over Load, Over Temperature, and Over Voltage features. Enhanced protection in substitutes does not reduce compatibility but may improve circuit reliability.