FQB6N70TM N-Channel MOSFET Equivalent & Substitute Parts

Part Overview

The FQB6N70TM is an N-Channel MOSFET manufactured by onsemi, rated for 700V drain-to-source voltage with 6.2A continuous drain current. This device is housed in a TO-263 (D2PAK) surface mount package and is part of the QFET® series. The FQB6N70TM is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, production continuity, and component sourcing.

Substitute parts must maintain functional compatibility within the same package type and satisfy the electrical parameter requirements of the original application circuit.

Substiute Parts

FQB6N70TM

onsemiIn Stock: 15692FQB6N70TM Datasheet

Current PartRFQ

STB5N80K5

STMicroelectronicsIn Stock: 3416STB5N80K5 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FQB6N70TM is determined by the following critical electrical and mechanical parameters:

Mandatory Compatibility Criteria:

• FET Type: N-Channel topology
• Package Type: TO-263 (D2PAK) surface mount configuration
• Drain-to-Source Voltage (Vdss): Equal to or greater than 700V
• Continuous Drain Current (Id): Equal to or greater than 6.2A at 25°C
• Gate Drive Voltage: 10V maximum Rds On specification
• Gate Threshold Voltage (Vgs(th)): Maximum 5V @ 250µA
• Maximum Gate Voltage (Vgs): ±30V or greater
• Operating Temperature Range: -55°C to 150°C or wider
• Moisture Sensitivity Level: MSL 1 (Unlimited) or equivalent

Substitute Part Identified:

The STB5N80K5 (STMicroelectronics) meets the mandatory package and topology requirements. However, this substitute exhibits reduced continuous drain current (4A versus 6.2A) and lower Vdss rating (800V versus 700V). The STB5N80K5 is suitable for applications where the reduced current rating is acceptable and where the higher voltage rating provides design margin.

Parameter Comparison

Engineering Selection Recommendations

FQB6N70TM (onsemi) — Original Part

• Product Status: Obsolete
• REACH Status: REACH Unaffected
• ECCN Classification: EAR99
• Inventory Status: 15,590 pieces available

The FQB6N70TM is obsolete and no longer in active production. Existing inventory is available through authorized distributors. For new designs or long-term production requirements, transition to an active substitute is recommended.

STB5N80K5 (STMicroelectronics) — Substitute Part

• Product Status: Active
• RoHS Status: ROHS3 Compliant
• REACH Status: REACH Unaffected
• ECCN Classification: EAR99
• Inventory Status: 3,400 pieces available
• Packaging: Cut Tape (CT) & Digi-Reel®

The STB5N80K5 is an active product with current manufacturing support and RoHS3 compliance certification. This substitute is suitable for applications where the reduced continuous drain current (4A versus 6.2A) and higher voltage rating (800V versus 700V) are compatible with circuit requirements. The STB5N80K5 exhibits lower gate charge (5 nC versus 40 nC) and significantly lower input capacitance (177 pF versus 1400 pF), which may improve switching performance in certain applications.

Frequently Asked Questions (FAQ)

Q: Can the STB5N80K5 directly replace the FQB6N70TM in all applications?

A: Direct replacement is possible only if the application circuit operates at drain currents of 4A or less. The STB5N80K5 is rated for 4A continuous drain current, compared to the FQB6N70TM's 6.2A rating. If the original design requires the full 6.2A capability, the STB5N80K5 is not suitable without circuit modification.

Q: What are the package compatibility considerations?

A: Both the FQB6N70TM and STB5N80K5 use the TO-263 (D2PAK) surface mount package with identical pinout and footprint. No PCB layout modifications are required for package compatibility.

Q: How does the higher voltage rating of the STB5N80K5 affect circuit operation?

A: The STB5N80K5 is rated for 800V Vdss compared to the FQB6N70TM's 700V. This higher voltage rating provides additional design margin and does not negatively affect circuits designed for 700V operation. The device will function correctly at or below 700V.

Q: What is the significance of the lower gate charge in the STB5N80K5?

A: The STB5N80K5 exhibits gate charge of 5 nC compared to 40 nC in the FQB6N70TM. Lower gate charge reduces the energy required to switch the device and may improve switching speed and reduce gate driver power consumption. This is a beneficial characteristic for high-frequency switching applications.

Q: Are there compliance or regulatory differences between these parts?

A: Both parts carry REACH Unaffected status and EAR99 ECCN classification. The STB5N80K5 includes RoHS3 compliance certification, while the FQB6N70TM does not specify RoHS status. For applications requiring RoHS compliance, the STB5N80K5 is the appropriate choice.

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

A: Both the FQB6N70TM and STB5N80K5 are classified as MSL 1 (Unlimited), indicating no moisture sensitivity restrictions during storage or handling.

Q: How do the thermal characteristics compare?

A: The FQB6N70TM is rated for 142W power dissipation at Tc (case temperature), while the STB5N80K5 is rated for 60W at Tc. The FQB6N70TM has superior thermal performance. For applications requiring high power dissipation, thermal management considerations may influence the substitution decision.