FSQ0370RLA Equivalent & Substitute Parts

Part Overview

The FSQ0370RLA is an offline switch flyback converter IC manufactured by onsemi, designed for isolated power management applications. This Active product operates at 100kHz switching frequency with 27W power capability and includes comprehensive fault protection (current limiting, overload, over-temperature, and over-voltage). The device is housed in an 8-LSOP surface mount package and is ROHS3 compliant.

Substitute parts are identified when equivalent functional performance can be achieved within the allowed electrical and mechanical parameters for offline flyback converter applications, particularly when the primary part is unavailable or when alternative packaging or performance characteristics better suit specific design requirements.

Substiute Parts

FSQ0370RLA

onsemiIn Stock: 1128FSQ0370RLA Datasheet

Current PartRFQ

NCP11184A100PG

onsemiIn Stock: 7004NCP11184A100PG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

The NCP11184A100PG qualifies as a substitute based on the following critical parameters:

• Topology Match: Both devices implement isolated flyback converter topology at 100kHz switching frequency
• Voltage Breakdown: NCP11184A100PG (800V) exceeds FSQ0370RLA (700V) requirement, providing enhanced voltage margin
• Supply Voltage Range: NCP11184A100PG (7.8V ~ 16V) overlaps with FSQ0370RLA (8V ~ 20V) within the 8V ~ 16V common operating window
• Switching Frequency: Both operate at 100kHz, ensuring compatible external component design
• Fault Protection: NCP11184A100PG includes all FSQ0370RLA protections plus additional Short Circuit and Open Loop protection
• Compliance: Both are ROHS3 compliant and REACH unaffected

Substitution is valid when the application operates within the overlapping supply voltage range (8V ~ 16V) and does not require the extended upper voltage capability (16V ~ 20V) of the FSQ0370RLA.

Parameter Comparison

Engineering Selection Recommendations

FSQ0370RLA is the primary selection when:

• Surface mount assembly is required
• Supply voltage extends to 20V
• Compact board space is critical
• Existing PCB layout is optimized for 8-LSOP package

NCP11184A100PG is a valid substitute when:

• Through-hole mounting is acceptable or preferred
• Supply voltage remains within 8V ~ 16V range
• Higher power capability (40W vs 27W) provides design margin
• Extended operating temperature range (-40°C ~ 150°C) is beneficial
• Additional fault protection features (Short Circuit, Open Loop) enhance system reliability
• Both devices are ROHS3 compliant and maintain equivalent regulatory status

Package and mounting type differences require PCB redesign; electrical parameter compatibility is confirmed within the specified voltage overlap range.

Frequently Asked Questions (FAQ)

Q: Can NCP11184A100PG directly replace FSQ0370RLA on the same PCB?

A: No. The devices use different package types (8-LSOP surface mount vs. 7-PDIP through-hole) and have different pin configurations. PCB redesign is required for physical and electrical integration.

Q: What is the critical voltage range for substitution?

A: Both devices operate within 8V ~ 16V. The FSQ0370RLA extends to 20V, while the NCP11184A100PG maximum is 16V. Substitution is valid only when the application supply voltage does not exceed 16V.

Q: Are there differences in switching frequency that affect component selection?

A: No. Both devices switch at 100kHz, so external transformer, inductor, and capacitor designs remain compatible.

Q: Does the higher power rating of NCP11184A100PG (40W vs 27W) affect compatibility?

A: The higher rating indicates greater capability and provides additional design margin. It does not create incompatibility; applications designed for 27W will operate within the NCP11184A100PG's specifications.

Q: What are the implications of the different fault protection features?

A: The NCP11184A100PG includes Short Circuit and Open Loop protection in addition to the FSQ0370RLA's protections. These additional features enhance system robustness and do not reduce compatibility.

Q: Is the extended operating temperature range of NCP11184A100PG (-40°C ~ 150°C vs -40°C ~ 85°C) a limiting factor?

A: No. The wider temperature range of NCP11184A100PG is a capability advantage. Applications operating within -40°C ~ 85°C will function correctly with either device.

Q: Are both parts equally available?

A: Inventory status is provided separately. FSQ0370RLA has 1092 pcs in stock; NCP11184A100PG has 6898 pcs in stock. Availability may influence selection when immediate delivery is required.

Q: Do compliance certifications differ between the two parts?

A: No. Both are ROHS3 compliant, REACH unaffected, and carry identical ECCN and HTSUS classifications.