FSQ0265RN Equivalent & Substitute Parts

Part Overview

The FSQ0265RN is an offline switch flyback converter IC manufactured by onsemi, designed for isolated power management applications. This device operates in the FPS™ series with a 55kHz to 67kHz switching frequency and delivers up to 20W of power. The FSQ0265RN is classified as obsolete, making identification of equivalent and substitute parts essential for design continuity and procurement planning. Active alternatives with comparable or enhanced specifications are available to support ongoing production and new designs.

Substiute Parts

FSQ0265RN

onsemiIn Stock: 1816FSQ0265RN Datasheet

Current PartRFQ

NCP1077AAP065G

onsemiIn Stock: 800NCP1077AAP065G Datasheet

MFR RecommendedRFQ

FSQ0365RN

onsemiIn Stock: 5980FSQ0365RN Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FSQ0265RN are identified based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Topology: Flyback converter architecture
• Output Isolation: Isolated configuration
• Internal Switch(es): Integrated power switch
• Voltage - Breakdown: Minimum 650V rating
• Voltage - Supply Range: Overlap with 8V ~ 20V input specification
• Frequency - Switching: Compatible switching frequency range
• Fault Protection: Presence of current limiting, over-temperature, and over-voltage protection
• Package / Case: Through-hole DIP configuration
• Mounting Type: Through-hole compatibility

Substitute Categories:

1. Parametric Equivalent (FSQ0365RN): Maintains identical topology, switching frequency range, breakdown voltage, supply voltage range, and package configuration. Differs in maximum power rating (25W vs. 20W) and product status (Active vs. Obsolete). Pin-compatible replacement with enhanced power capability.

2. Manufacturer Recommended Alternative (NCP1077AAP065G): Offers higher breakdown voltage (700V), extended operating temperature range (-40°C ~ 125°C), and increased power rating (31W). Switching frequency fixed at 65kHz within the compatible range. Package configuration is 7-PDIP with 7 leads, requiring PCB layout evaluation. Enhanced fault protection includes short-circuit detection.

Parameter Comparison

Engineering Selection Recommendations

FSQ0365RN - Recommended Primary Substitute: The FSQ0365RN is the optimal substitute for the obsolete FSQ0265RN. Both devices maintain identical electrical specifications including topology, breakdown voltage, supply voltage range, switching frequency, and package configuration. The FSQ0365RN is pin-compatible and offers increased power capability (25W vs. 20W). Active product status ensures long-term availability and supply chain continuity. ROHS3 compliance and identical fault protection features support direct replacement in existing designs.

NCP1077AAP065G - Alternative for Enhanced Performance: The NCP1077AAP065G provides higher breakdown voltage (700V), extended operating temperature range to 125°C, and increased power rating (31W). This device is suitable for applications requiring enhanced thermal performance or higher voltage margins. The 7-PDIP package configuration requires verification of PCB layout compatibility, as the lead count differs from the 8-DIP configuration. Active product status and ROHS3 compliance support new design implementations. Enhanced fault protection including short-circuit detection provides additional system robustness.

Frequently Asked Questions (FAQ)

Q: Can FSQ0365RN directly replace FSQ0265RN without PCB modifications? A: Yes. The FSQ0365RN maintains identical package configuration (8-DIP), pin count, and electrical specifications. Direct pin-for-pin replacement is supported without PCB layout changes.

Q: What are the key differences between FSQ0365RN and NCP1077AAP065G? A: The FSQ0365RN maintains the original 8-DIP package and switching frequency range (55kHz ~ 67kHz). The NCP1077AAP065G uses a 7-PDIP package with fixed 65kHz switching frequency, offers higher breakdown voltage (700V vs. 650V), extended temperature range (-40°C ~ 125°C vs. -40°C ~ 85°C), and increased power rating (31W vs. 25W). Package differences require PCB evaluation.

Q: Is the NCP1077AAP065G package compatible with existing FSQ0265RN PCB layouts? A: The NCP1077AAP065G uses a 7-PDIP package with 7 leads, while the FSQ0265RN uses an 8-DIP package with 8 leads. Physical package dimensions are similar (8-DIP 0.300", 7.62mm), but lead count and pinout differences require PCB layout verification before implementation.

Q: Are all substitute parts ROHS3 compliant? A: Yes. FSQ0365RN and NCP1077AAP065G are both ROHS3 compliant, matching the compliance status of the original FSQ0265RN.

Q: What is the supply voltage range compatibility for substitutes? A: FSQ0365RN maintains the original 8V ~ 20V range. NCP1077AAP065G extends the lower limit to 6.5V, providing broader input voltage compatibility while maintaining the 20V upper limit.

Q: Which substitute is recommended for new designs? A: FSQ0365RN is recommended for designs requiring direct compatibility with existing FSQ0265RN specifications. NCP1077AAP065G is recommended for applications requiring enhanced performance specifications including higher breakdown voltage, extended temperature range, or increased power capability.