TOP257PG Equivalent & Substitute Parts Reference

Part Overview

The TOP257PG is an offline switch flyback converter IC from Power Integrations' TOPSwitch®-HX series, designed for isolated power supply applications. This 8-DIP package component operates at 66 kHz switching frequency with 41 W power capability and 700 V breakdown voltage rating. The device is Active status and RoHS Compliant, suitable for direct component selection in flyback topology designs. Alternative models within the TOPSwitch®-HX family are available to accommodate different power output requirements while maintaining electrical and mechanical compatibility.

Substiute Parts

TOP257PG

Power IntegrationsIn Stock: 1153TOP257PG Datasheet

Current PartRFQ

TOP252PN

Power IntegrationsIn Stock: 16863TOP252PN Datasheet

Parametric EquivalentRFQ

TOP253PN

Power IntegrationsIn Stock: 35327TOP253PN Datasheet

Parametric EquivalentRFQ

TOP254PN

Power IntegrationsIn Stock: 20365TOP254PN Datasheet

Parametric EquivalentRFQ

TOP255PN

Power IntegrationsIn Stock: 5712TOP255PN Datasheet

Parametric EquivalentRFQ

TOP256PN

Power IntegrationsIn Stock: 19162TOP256PN Datasheet

Parametric EquivalentRFQ

TOP257PN

Power IntegrationsIn Stock: 1358TOP257PN Datasheet

Parametric EquivalentRFQ

TOP258PN

Power IntegrationsIn Stock: 25324TOP258PN Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts within the TOPSwitch®-HX series maintain identical electrical and mechanical characteristics across the following parameters:

Fixed Parameters (All Substitutes Match):

• Topology: Flyback
• Output Isolation: Isolated
• Voltage - Breakdown: 700V
• Frequency - Switching: 66 kHz
• Duty Cycle: 78%
• Package / Case: 8-DIP (0.300", 7.62mm), 7 Leads
• Mounting Type: Through Hole
• Operating Temperature: -40°C ~ 150°C (TJ)
• Fault Protection: Current Limiting, Over Temperature, Over Voltage
• Series: TOPSwitch®-HX
• Product Status: Active
• RoHS Status: RoHS Compliant
• Moisture Sensitivity Level (MSL): 1 (Unlimited)

Variable Parameter (Differentiates Substitutes):

• Power (Watts): Ranges from 15 W to 48 W across the substitute family

Substitution is valid when the alternative part's power rating meets or exceeds the application requirement while maintaining identical package, topology, isolation, voltage rating, and switching characteristics.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts listed are Active status components with RoHS Compliance and MSL Level 1 (Unlimited) moisture sensitivity rating, meeting the same regulatory and environmental standards as the TOP257PG.

Selection Criteria Based on Power Requirements:

For applications requiring 41 W output, TOP257PN provides identical electrical specifications with higher inventory availability (1,308 pcs vs. 1,057 pcs for TOP257PG). Both parts are functionally equivalent with identical package configuration.

For applications with lower power requirements, substitute parts with reduced wattage ratings (TOP252PN through TOP256PN) are electrically compatible and mechanically interchangeable. Selection should be based on the minimum power rating required by the application design.

For applications requiring power output exceeding 41 W, TOP258PN (48 W) is the only available substitute within this series, offering the highest power capability while maintaining all other electrical and mechanical parameters.

All parts maintain identical 700V breakdown voltage, 66 kHz switching frequency, 78% duty cycle, and 8-DIP through-hole package configuration, ensuring direct PCB compatibility without layout modifications.

Frequently Asked Questions (FAQ)

Q: Can TOP257PG be replaced with TOP257PN?

A: Yes. Both parts are identical in electrical specifications (41 W power rating, 700V breakdown, 66 kHz switching frequency, 78% duty cycle) and mechanical configuration (8-DIP through-hole package). The difference is packaging designation (PG vs. PN tube packaging). Both are Active status, RoHS Compliant, and MSL Level 1.

Q: What is the primary difference between substitute parts in this family?

A: The power rating (watts) is the only variable parameter. All other specifications—topology, isolation, voltage rating, switching frequency, duty cycle, package type, and operating temperature range—remain constant across the entire TOPSwitch®-HX family listed.

Q: Can TOP252PN (15 W) be used in place of TOP257PG (41 W)?

A: No. TOP252PN has a lower power rating (15 W) than TOP257PG (41 W). Substitution requires the alternative part to meet or exceed the application's power requirement. TOP252PN is suitable only for applications designed for 15 W or lower output.

Q: Are all substitute parts pin-compatible with TOP257PG?

A: Yes. All parts use the identical 8-DIP (0.300", 7.62mm) package with 7 leads and through-hole mounting configuration. No PCB layout modifications are required for substitution.

Q: What is the operating temperature range for all parts?

A: All parts operate from -40°C to 150°C junction temperature (TJ), providing identical thermal performance specifications.

Q: Do all substitute parts include the same fault protection features?

A: Yes. All parts include Current Limiting, Over Temperature, and Over Voltage protection, ensuring equivalent safety and reliability characteristics.

Q: Which substitute part has the highest inventory availability?

A: TOP253PN (25 W) has the highest inventory with 35,300 pieces in stock, followed by TOP258PN (48 W) with 25,300 pieces.

Q: Can TOP258PN (48 W) be used in applications designed for TOP257PG (41 W)?

A: Yes. TOP258PN exceeds the power requirement of TOP257PG while maintaining all other electrical and mechanical specifications. It is suitable for direct substitution in applications designed for 41 W or lower output.