FDH5500 Equivalent & Substitute Parts

Part Overview

The FDH5500 is an N-Channel MOSFET rated for 55V drain-to-source voltage with 75A continuous drain current in a TO-247-3 through-hole package. Manufactured by onsemi as part of the UltraFET™ series, this device is designed for high-current switching applications requiring robust thermal performance and low on-state resistance.

The FDH5500 carries an Obsolete product status. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain availability, and support ongoing production requirements for applications currently utilizing this component.

Substiute Parts

FDH5500

onsemiIn Stock: 33665FDH5500 Datasheet

Current PartRFQ

HUF75344G3

onsemiIn Stock: 1278HUF75344G3 Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FDH5500 is determined by electrical and mechanical compatibility across the following critical parameters:

Electrical Compatibility Criteria:

• Drain-to-Source Voltage (Vdss): Must equal or exceed 55V
• Continuous Drain Current (Id): Must equal or exceed 75A at 25°C
• Gate Threshold Voltage (Vgs(th)): Must be compatible with existing gate drive circuits
• On-State Resistance (Rds On): Lower values indicate improved performance; higher values remain acceptable if within thermal limits
• Operating Temperature Range: Must encompass -55°C to 175°C

Mechanical Compatibility Criteria:

• Package Type: TO-247-3 through-hole configuration required for direct PCB mounting compatibility
• Mounting Type: Through-hole mounting mandatory for existing board layouts

The HUF75344G3 meets all electrical and mechanical substitution criteria for the FDH5500, maintaining identical voltage and current ratings while operating within the same temperature range and package footprint.

Parameter Comparison

Engineering Selection Recommendations

HUF75344G3 as Primary Substitute:

The HUF75344G3 is the direct substitute for the obsolete FDH5500. Both devices are manufactured by onsemi within the UltraFET™ series and share identical electrical ratings for voltage (55V Vdss) and current (75A Id). The HUF75344G3 maintains Active product status, ensuring long-term availability and supply chain support.

Compliance and Regulatory Status:

Both the FDH5500 and HUF75344G3 carry REACH Unaffected status and EAR99 ECCN classification. The HUF75344G3 additionally carries RoHS3 Compliance certification, meeting modern environmental and regulatory requirements for new designs and production runs.

Thermal and Performance Considerations:

The HUF75344G3 exhibits a slightly higher on-state resistance (8 mOhm versus 7 mOhm) and lower maximum power dissipation rating (285W versus 375W). These differences reflect design optimization in the active part. The HUF75344G3 also demonstrates lower gate charge (210 nC versus 268 nC) and reduced input capacitance (3200 pF versus 3565 pF), resulting in improved switching efficiency.

The HUF75344G3 operates within a ±20V gate voltage range compared to the FDH5500's ±30V range. Existing gate drive circuits designed for the FDH5500 must operate within the ±20V specification to ensure compatibility.

Packaging and Mounting:

Both devices utilize identical TO-247-3 through-hole packaging, enabling direct PCB footprint compatibility without layout modifications.

Frequently Asked Questions (FAQ)

Q: Can the HUF75344G3 directly replace the FDH5500 in existing designs?

A: Yes. The HUF75344G3 provides direct electrical and mechanical compatibility. Both devices share identical Vdss (55V), Id (75A), Vgs(th) (4V), and TO-247-3 package specifications. Gate drive circuits must operate within the HUF75344G3's ±20V maximum gate voltage specification.

Q: What are the key differences between the FDH5500 and HUF75344G3?

A: The primary differences are: (1) Product Status—FDH5500 is Obsolete; HUF75344G3 is Active; (2) On-state resistance—FDH5500 is 7 mOhm; HUF75344G3 is 8 mOhm; (3) Power dissipation rating—FDH5500 is 375W; HUF75344G3 is 285W; (4) Gate charge—FDH5500 is 268 nC; HUF75344G3 is 210 nC; (5) Maximum gate voltage—FDH5500 is ±30V; HUF75344G3 is ±20V; (6) Compliance—HUF75344G3 carries RoHS3 Compliance certification.

Q: Are there thermal management implications when substituting the FDH5500 with the HUF75344G3?

A: The HUF75344G3 has a lower maximum power dissipation rating (285W versus 375W). Applications operating near the FDH5500's thermal limits require thermal analysis to confirm the HUF75344G3 remains within acceptable operating conditions. The lower gate charge and input capacitance of the HUF75344G3 may reduce switching losses, partially offsetting the higher on-state resistance.

Q: Is the TO-247-3 package identical between both devices?

A: Yes. Both the FDH5500 and HUF75344G3 use the TO-247-3 through-hole package with identical mechanical dimensions and PCB footprint compatibility.

Q: What is the significance of the HUF75344G3's Active product status?

A: Active product status indicates the HUF75344G3 is in current production with established long-term supply chain support. This contrasts with the FDH5500's Obsolete status, which indicates discontinued production and limited availability. Transitioning to the HUF75344G3 ensures sustained component availability for ongoing and future production requirements.

Q: Does the HUF75344G3 meet modern regulatory requirements?

A: Yes. The HUF75344G3 carries RoHS3 Compliance certification and maintains REACH Unaffected status, meeting current environmental and regulatory standards for electronic components in most jurisdictions.

Q: Can gate drive circuits designed for ±30V operation be used with the HUF75344G3?

A: Gate drive circuits must not exceed the HUF75344G3's ±20V maximum gate voltage specification. Circuits designed for ±30V operation require modification or replacement to ensure safe and reliable operation within the HUF75344G3's voltage limits.