FDMS3668S MOSFET Equivalent & Substitute Parts

Part Overview

The FDMS3668S is a dual N-channel MOSFET manufactured by onsemi, rated for 30V drain-to-source voltage with continuous drain current ratings of 13A and 18A. This component features logic-level gate operation and is housed in an 8-PowerTDFN (Power56) surface mount package. The FDMS3668S is classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing design support and production continuity. The part operates across a temperature range of -55°C to 150°C and complies with ROHS3 and REACH standards.

Substiute Parts

FDMS3668S

onsemiIn Stock: 17435FDMS3668S Datasheet

Current PartRFQ

STL66DN3LLH5

STMicroelectronicsIn Stock: 22720STL66DN3LLH5 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDMS3668S is determined by electrical and mechanical compatibility across the following critical parameters:

Voltage Rating Compatibility: The substitute part must maintain the 30V Vdss rating to ensure safe operation within the same voltage domain.

Drain Current Capability: The substitute must support continuous drain current at or above the 13A and 18A ratings specified for the FDMS3668S to maintain equivalent current-handling capacity.

Gate-Level Operation: Logic-level gate operation is required to ensure compatibility with standard digital control signals without additional gate drive circuitry.

Configuration: Dual N-channel configuration is mandatory to preserve the functional architecture of the original design.

Package and Mounting: Surface mount technology with compatible pinout and thermal characteristics is required for direct board-level substitution.

Compliance Standards: RoHS3 compliance and REACH unaffected status ensure regulatory alignment with modern manufacturing and environmental requirements.

The STL66DN3LLH5 from STMicroelectronics meets these substitution criteria while offering enhanced electrical performance characteristics.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The FDMS3668S is classified as obsolete, whereas the STL66DN3LLH5 maintains active product status with ongoing manufacturer support and availability. Selection of an active product ensures long-term supply chain reliability and access to technical documentation.

Compliance and Certification: Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment. The STL66DN3LLH5 carries AEC-Q101 automotive qualification, providing additional assurance for applications requiring automotive-grade reliability standards.

Electrical Performance: The STL66DN3LLH5 demonstrates superior electrical characteristics, including higher continuous drain current capacity (78.5A versus 13A/18A), lower on-state resistance (6.5mOhm versus 8mOhm), and reduced gate charge (12nC versus 29nC). These improvements result in lower power dissipation and faster switching response.

Thermal Performance: The STL66DN3LLH5 supports an extended operating temperature range (-55°C to 175°C versus -55°C to 150°C) and significantly higher maximum power dissipation (72W versus 1W), enabling operation in more demanding thermal environments.

Package Compatibility: The substitute part uses an 8-PowerVDFN (PowerFlat 5x6) package instead of the 8-PowerTDFN (Power56) package. PCB layout modifications are required to accommodate the different package footprint and thermal characteristics.

Frequently Asked Questions (FAQ)

Q: Can the STL66DN3LLH5 directly replace the FDMS3668S without PCB modifications?

A: No. While both parts are dual N-channel MOSFETs with 30V ratings and logic-level gate operation, they use different package types. The FDMS3668S uses an 8-PowerTDFN (Power56) package, while the STL66DN3LLH5 uses an 8-PowerVDFN (PowerFlat 5x6) package. PCB layout redesign is required to accommodate the different footprint and thermal pad configuration.

Q: What are the key electrical parameters that determine substitution compatibility?

A: Substitution compatibility is determined by: (1) matching or exceeding the 30V drain-to-source voltage rating, (2) continuous drain current capability at or above 13A/18A, (3) logic-level gate operation for control signal compatibility, (4) dual N-channel configuration, and (5) surface mount technology with compatible pinout.

Q: Does the STL66DN3LLH5 offer performance advantages over the FDMS3668S?

A: Yes. The STL66DN3LLH5 provides higher continuous drain current (78.5A), lower on-state resistance (6.5mOhm), reduced gate charge (12nC), and significantly higher power dissipation capability (72W). These characteristics result in improved efficiency and thermal performance.

Q: Is the STL66DN3LLH5 suitable for automotive applications?

A: Yes. The STL66DN3LLH5 carries AEC-Q101 automotive qualification and is designated as automotive grade, making it suitable for automotive applications requiring qualified components.

Q: What is the moisture sensitivity level for both parts?

A: Both the FDMS3668S and STL66DN3LLH5 have a Moisture Sensitivity Level (MSL) of 1 (Unlimited), indicating no moisture sensitivity restrictions during storage and handling.

Q: Are both parts RoHS3 compliant?

A: Yes. Both the FDMS3668S and STL66DN3LLH5 are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Q: What is the temperature operating range difference between these parts?

A: The FDMS3668S operates from -55°C to 150°C (TJ), while the STL66DN3LLH5 operates from -55°C to 175°C (TJ). The STL66DN3LLH5 supports a 25°C higher maximum junction temperature, enabling operation in higher-temperature environments.