TOP233PN Equivalent & Substitute Parts Reference

Part Overview

The TOP233PN is an offline flyback converter IC manufactured by Power Integrations, part of the TOPSwitch®-FX series. This 8-DIP through-hole component integrates a 700V breakdown voltage switch with frequency control capability, designed for isolated power supply applications with 25W output capacity. The device operates across a 66kHz to 132kHz switching frequency range with 78% duty cycle and includes comprehensive fault protection features including current limiting, over-temperature, and over-voltage protection.

The TOP233PN is classified as obsolete. Identifying equivalent and substitute parts is necessary to support ongoing production requirements, field repairs, and design continuity where this component is specified in existing applications.

Substiute Parts

TOP233PN

Power IntegrationsIn Stock: 1386TOP233PN Datasheet

Current PartRFQ

TOP253PN

Power IntegrationsIn Stock: 35327TOP253PN Datasheet

MFR RecommendedRFQ

TOP243PN

Power IntegrationsIn Stock: 1602TOP243PN Datasheet

SimilarRFQ

NCP1077P130G

onsemiIn Stock: 713NCP1077P130G Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the TOP233PN is determined by the following critical parameters:

Primary Compatibility Criteria:

• Topology: Flyback converter architecture
• Output Isolation: Isolated configuration
• Voltage - Breakdown: 700V minimum
• Power Rating: 25W nominal output
• Package / Case: 8-DIP through-hole form factor
• Mounting Type: Through Hole
• Operating Temperature Range: Minimum -40°C to 150°C

Secondary Compatibility Criteria:

• Switching Frequency: 66kHz to 132kHz range (or subset thereof)
• Duty Cycle: 78% nominal (or compatible range)
• Fault Protection: Current Limiting, Over Temperature, Over Voltage
• Control Features: Frequency Control capability

Substitute parts are classified into two categories:

MFR Recommended Substitute: TOP253PN represents the manufacturer-recommended direct replacement, offering active product status and identical electrical specifications within the primary criteria.

Similar Substitutes: TOP243PN and NCP1077P130G provide functional equivalence within the primary criteria but differ in secondary parameters such as duty cycle, switching frequency characteristics, or control features. These parts are suitable where application requirements accommodate the specified parameter variations.

Parameter Comparison

Engineering Selection Recommendations

TOP253PN - MFR Recommended Substitute

The TOP253PN is the manufacturer-recommended equivalent for TOP233PN applications. This part maintains identical electrical specifications across all primary compatibility criteria: 700V breakdown voltage, 25W power rating, 78% duty cycle, isolated flyback topology, and 8-DIP through-hole package. The TOP253PN carries Active product status, ensuring long-term availability and ongoing manufacturer support. Both parts are RoHS Compliant with MSL 1 rating. The primary distinction is that TOP253PN operates at a fixed 66kHz switching frequency rather than the variable 66kHz to 132kHz range of TOP233PN, and lacks explicit frequency control features. This substitution is appropriate for applications where fixed-frequency operation is acceptable.

TOP243PN - Similar Substitute

The TOP243PN provides functional equivalence within primary compatibility criteria but is designated Not For New Designs. This part maintains 700V breakdown voltage, 25W power rating, isolated flyback topology, and 8-DIP through-hole package. TOP243PN retains frequency control capability and operates across the 66kHz to 132kHz switching frequency range. The duty cycle differs at 66.5% compared to TOP233PN's 78%. This substitution is suitable for existing production support where duty cycle variation is within application tolerance and frequency control functionality is required.

NCP1077P130G - Similar Substitute

The NCP1077P130G is a onsemi alternative offering equivalent power rating (25W) and isolated flyback topology in 8-DIP through-hole package. This part is classified as Obsolete. The NCP1077P130G operates at fixed 130kHz switching frequency with 69% duty cycle and includes expanded fault protection (Over Load, Over Temperature, Over Voltage, Short Circuit). Operating temperature range is -40°C to 125°C, which is 25°C lower than TOP233PN. This substitution is applicable where fixed high-frequency operation and enhanced short-circuit protection are beneficial, and the reduced upper temperature limit is acceptable.

Frequently Asked Questions (FAQ)

Q: Can TOP253PN directly replace TOP233PN in existing designs?

A: TOP253PN is the manufacturer-recommended substitute and maintains identical electrical specifications for primary compatibility criteria. However, TOP253PN operates at fixed 66kHz frequency rather than the variable 66kHz to 132kHz range of TOP233PN. Applications requiring frequency control or variable frequency operation must evaluate whether fixed-frequency operation is acceptable. Pin-to-pin compatibility and package form factor are identical.

Q: What is the key difference between TOP233PN and TOP243PN?

A: Both parts operate across 66kHz to 132kHz switching frequency range and include frequency control capability. The primary difference is duty cycle: TOP233PN operates at 78% while TOP243PN operates at 66.5%. TOP243PN is designated Not For New Designs. This substitution is suitable where duty cycle variation is within application tolerance.

Q: Why does NCP1077P130G have a lower maximum operating temperature?

A: NCP1077P130G specifies -40°C to 125°C (TJ) compared to TOP233PN's -40°C to 150°C (TJ). This 25°C difference reflects the thermal design characteristics of the onsemi device. Applications operating near or above 125°C junction temperature require verification that NCP1077P130G thermal performance is adequate.

Q: Are all substitute parts RoHS compliant?

A: Yes. TOP233PN, TOP253PN, and TOP243PN are RoHS Compliant. NCP1077P130G is ROHS3 Compliant. All parts meet current RoHS requirements and are suitable for applications with RoHS compliance mandates.

Q: What is the significance of the 8-DIP package designation?

A: All listed parts use 8-DIP (0.300", 7.62mm) through-hole package with 7 leads. This identical package specification ensures mechanical and electrical compatibility on existing PCB layouts. No board redesign is required for substitution.

Q: Can NCP1077P130G be used in applications requiring frequency control?

A: No. NCP1077P130G does not include frequency control features and operates at fixed 130kHz switching frequency. This part is suitable only for applications where fixed-frequency operation is acceptable.

Q: What fault protection features are common across all substitute parts?

A: All parts include Over Temperature and Over Voltage protection. TOP233PN, TOP253PN, and TOP243PN include Current Limiting protection. NCP1077P130G includes Over Load and Short Circuit protection in addition to Over Temperature and Over Voltage. Application requirements for specific fault protection types should guide substitution selection.