FDMF6704 Equivalent & Substitute Parts

Part Overview

The FDMF6704 is a half bridge driver IC designed for synchronous buck converter applications. Manufactured by onsemi, this DrMOS device integrates gate driver and power MOSFET functionality in a 40-MLP package. The part is currently in Last Time Buy status, making identification of equivalent alternatives essential for design continuity and long-term supply chain planning. Substitute parts must maintain functional compatibility across output configuration, interface protocol, fault protection, and thermal operating range.

Substiute Parts

FDMF6704

onsemiIn Stock: 16472FDMF6704 Datasheet

Current PartRFQ

FDMF6704

Fairchild SemiconductorIn Stock: 16460FDMF6704 Datasheet

DirectRFQ

CSD97370Q5M

Texas InstrumentsIn Stock: 17457CSD97370Q5M Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FDMF6704 are identified based on strict parameter alignment in the following categories:

Functional Equivalence Criteria:

• Output Configuration: Half Bridge (required match)
• Interface: PWM (required match)
• Fault Protection: Shoot-Through and UVLO (required match)
• Features: Bootstrap Circuit (required match)
• Load Type: Inductive (required match)
• Applications: Synchronous Buck Converters (required match)

Electrical Compatibility Criteria:

• Voltage - Supply: 4.5V ~ 5.5V (required match)
• Current - Output / Channel: 35A minimum
• Current - Peak Output: 60A minimum
• Operating Temperature: Must support -55°C ~ 150°C range or equivalent industrial range
• Voltage - Load: Must support 3V ~ 14V range or broader

Physical & Compliance Criteria:

• Mounting Type: Surface Mount (required match)
• RoHS Status: ROHS3 Compliant (required match)
• REACH Status: REACH Unaffected (required match)

Parameter Comparison

Engineering Selection Recommendations

Direct Equivalent (Preferred): The FDMF6704 from Fairchild Semiconductor is a direct functional equivalent with identical electrical specifications, package footprint, and operating parameters. Both onsemi and Fairchild versions share the same base product number and DrMOS technology platform. This part is currently in Active status, providing supply continuity for the Last Time Buy onsemi variant. Selection of the Fairchild version eliminates design re-qualification requirements.

Functional Alternative (Design Consideration Required): The CSD97370Q5M from Texas Instruments meets core functional requirements for half bridge driver applications with PWM interface and integrated fault protection. However, this part introduces the following design considerations:

• Package change from 40-WFQFN to 22-PowerLFDFN requires PCB layout modification
• Peak output current specification (60A) is lower than the FDMF6704 (80A)
• Operating temperature minimum is -40°C versus -55°C for the original part
• Moisture sensitivity level is MSL 2 (1 Year) versus MSL 1 (Unlimited)
• Load voltage range is broader (3.3V ~ 22V), providing additional application flexibility

Selection of the CSD97370Q5M is appropriate only when PCB redesign is feasible and the reduced peak current and narrower low-temperature operating range do not conflict with system requirements.

Frequently Asked Questions (FAQ)

Q: Can the FDMF6704 be directly replaced with the Fairchild FDMF6704? A: Yes. Both parts share identical electrical specifications, package geometry, and functional characteristics. No design changes are required. The Fairchild version is recommended as the primary substitute due to Active product status and supply availability.

Q: What are the key differences between the FDMF6704 and CSD97370Q5M? A: The primary differences are package type (40-WFQFN versus 22-PowerLFDFN), peak output current (80A versus 60A), minimum operating temperature (-55°C versus -40°C), and moisture sensitivity level (MSL 1 versus MSL 2). The CSD97370Q5M requires PCB layout redesign and is suitable only when these parameter differences are acceptable for the application.

Q: Is the CSD97370Q5M suitable for applications requiring -55°C operation? A: No. The CSD97370Q5M operates from -40°C to 150°C, which does not meet the -55°C minimum temperature requirement of the original FDMF6704. Applications requiring full -55°C to 150°C operation must use the FDMF6704 or Fairchild equivalent.

Q: What is the impact of the package change from 40-WFQFN to 22-PowerLFDFN? A: The package change requires complete PCB layout redesign, including trace routing, thermal management, and component placement. This is not a pin-compatible substitution and necessitates full design re-qualification and testing.

Q: Are all substitute parts RoHS3 compliant? A: The onsemi FDMF6704 and Texas Instruments CSD97370Q5M are both ROHS3 Compliant. Fairchild FDMF6704 RoHS status is not specified in the provided data.

Q: What is the moisture sensitivity level (MSL) consideration for long-term storage? A: The onsemi FDMF6704 has MSL 1 (Unlimited storage without baking). The CSD97370Q5M has MSL 2 (1 Year storage; baking required after 1 year). The Fairchild FDMF6704 MSL is not specified. For applications with extended storage periods, the onsemi MSL 1 rating provides operational flexibility.