FQS4903TF Equivalent & Substitute Parts

Part Overview

The FQS4903TF is a dual N-channel MOSFET array manufactured by onsemi, rated for 500V drain-to-source voltage with a continuous drain current of 370mA. This component is housed in an 8-SOIC surface mount package and is part of the QFET® series. The FQS4903TF is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support and production continuity. Substitute parts must maintain compatibility with the electrical specifications and physical packaging requirements of the original design.

Substiute Parts

FQS4903TF

onsemiIn Stock: 2842FQS4903TF Datasheet

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IRF7103TRPBF

Infineon TechnologiesIn Stock: 17412IRF7103TRPBF Datasheet

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SP8K80TB1

Rohm SemiconductorIn Stock: 20268SP8K80TB1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the FQS4903TF are evaluated based on the following critical parameters that determine functional compatibility:

Electrical Compatibility Criteria:

• Configuration: 2 N-Channel (Dual) MOSFET array
• Drain to Source Voltage (Vdss): Must equal or exceed 500V
• Continuous Drain Current (Id): Must support minimum 370mA
• Maximum Power Dissipation: Must equal or exceed 2W
• Operating Temperature Range: Must encompass -55°C to 150°C

Physical Compatibility Criteria:

• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Moisture Sensitivity Level: MSL 1 (Unlimited)

Regulatory Compliance:

• RoHS3 Compliant
• REACH Unaffected
• ECCN: EAR99

The substitute parts listed below meet these criteria with the following considerations:

IRF7103TRPBF (Infineon Technologies): Shares identical package footprint and surface mount configuration. However, this part operates at 50V Vdss, which is significantly lower than the 500V requirement of the FQS4903TF. This part is not suitable for direct substitution in applications requiring 500V operation.

SP8K80TB1 (Rohm Semiconductor): Maintains the 500V Vdss rating and 2W power dissipation. Continuous drain current is rated at 500mA (Ta), which exceeds the 370mA requirement. Package footprint is compatible (8-SOIC). This part qualifies as a direct substitute based on electrical and physical parameters.

Parameter Comparison

Engineering Selection Recommendations

SP8K80TB1 (Rohm Semiconductor) is the qualified substitute for the FQS4903TF based on the following engineering criteria:

1. Voltage Rating Compatibility: Both parts are rated for 500V Vdss, meeting the primary electrical requirement for high-voltage applications.

2. Current Capacity: The SP8K80TB1 provides 500mA continuous drain current, which exceeds the FQS4903TF specification of 370mA, ensuring adequate current handling capability.

3. Power Dissipation: Both parts are rated for 2W maximum power dissipation, maintaining thermal design compatibility.

4. Package Compatibility: The SP8K80TB1 is housed in an 8-SOIC package with identical footprint dimensions (0.154", 3.90mm Width), allowing direct PCB layout compatibility.

5. Regulatory Compliance: The SP8K80TB1 meets ROHS3 compliance, REACH unaffected status, and MSL 1 rating, matching the compliance profile of the original part.

6. Product Status: The SP8K80TB1 is classified as active, ensuring ongoing availability and manufacturing support.

IRF7103TRPBF (Infineon Technologies) is not suitable as a substitute due to its 50V Vdss rating, which is insufficient for applications designed for the FQS4903TF's 500V operating voltage. This part is only applicable in designs requiring lower voltage operation.

Frequently Asked Questions (FAQ)

Q: Can the IRF7103TRPBF be used as a substitute for the FQS4903TF?

A: No. The IRF7103TRPBF is rated for 50V Vdss, while the FQS4903TF is rated for 500V Vdss. Using the IRF7103TRPBF in a 500V application will result in device failure. This part is only suitable for applications operating at 50V or lower.

Q: What is the primary reason the SP8K80TB1 qualifies as a substitute?

A: The SP8K80TB1 maintains the critical electrical specifications of the FQS4903TF: 500V Vdss rating, 2W power dissipation, and dual N-channel configuration. It also shares the identical 8-SOIC package footprint, enabling direct PCB compatibility without layout modifications.

Q: Are there any differences in gate charge between the FQS4903TF and SP8K80TB1?

A: Yes. The SP8K80TB1 has a lower gate charge of 3.8nC @ 10V compared to the FQS4903TF's 8.2nC @ 10V. Lower gate charge results in faster switching characteristics and reduced gate drive power requirements, which is beneficial for circuit performance.

Q: Does the SP8K80TB1 have the same operating temperature range as the FQS4903TF?

A: The operating temperature range for the SP8K80TB1 is not specified in the available data. The FQS4903TF operates from -55°C to 150°C (TJ). Verify the SP8K80TB1 temperature specifications with the manufacturer datasheet before use in temperature-critical applications.

Q: Are both the FQS4903TF and SP8K80TB1 RoHS compliant?

A: Yes. Both parts are ROHS3 compliant, REACH unaffected, and carry MSL 1 (Unlimited) moisture sensitivity ratings, meeting current environmental and regulatory requirements.

Q: What is the difference in on-resistance (Rds On) between these parts?

A: The FQS4903TF has Rds On of 6.2Ohm @ 185mA, 10V, while the SP8K80TB1 has Rds On of 11.7Ohm @ 250mA, 10V. The SP8K80TB1's higher on-resistance may result in increased power dissipation at higher current levels. Verify thermal performance in your specific application.

Q: Can I use the SP8K80TB1 in place of the FQS4903TF without modifying the PCB?

A: Yes. Both parts use the 8-SOIC package with identical footprint dimensions (0.154", 3.90mm Width), allowing direct component substitution without PCB layout changes.