FQB2N90TM Equivalent & Substitute Parts

Part Overview

The FQB2N90TM is an N-Channel MOSFET manufactured by onsemi, rated for 900V drain-to-source voltage with a continuous drain current of 2.2A at 25°C. This device is packaged in a Surface Mount TO-263 (D2PAK) configuration and is part of the QFET® series. The FQB2N90TM is classified as obsolete, making identification of equivalent and substitute parts essential for ongoing design support, maintenance, and production continuity. Substitute parts must maintain functional compatibility within the electrical and mechanical constraints of the original application.

Substiute Parts

FQB2N90TM

onsemiIn Stock: 1053FQB2N90TM Datasheet

Current PartRFQ

IRF540NSTRLPBF

Infineon TechnologiesIn Stock: 35365IRF540NSTRLPBF Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the FQB2N90TM requires strict adherence to the following electrical and mechanical parameters:

Critical Substitution Criteria:

1. Drain-to-Source Voltage (Vdss): The substitute must equal or exceed 900V to maintain voltage withstand capability in the original circuit topology.

2. Continuous Drain Current (Id): The substitute must support a minimum of 2.2A continuous drain current at 25°C to ensure adequate current handling without thermal stress.

3. On-State Resistance (Rds On): The substitute must maintain comparable or lower on-state resistance to preserve power efficiency and thermal performance characteristics.

4. Gate Drive Voltage: The substitute must operate with a 10V gate drive voltage to ensure compatibility with existing gate driver circuits.

5. Package Configuration: The substitute must utilize the same Surface Mount TO-263 (D2PAK) package to maintain mechanical compatibility with printed circuit board layouts.

6. Operating Temperature Range: The substitute must support the operating temperature range of -55°C to 150°C (TJ) or exceed it to ensure thermal compatibility.

7. Gate Charge and Input Capacitance: These parameters must be within acceptable ranges to prevent gate driver circuit redesign.

The IRF540NSTRLPBF does not meet the critical voltage requirement (100V vs. 900V Vdss) and therefore cannot serve as a direct substitute for the FQB2N90TM. This part is listed in the provided substitute list but fails the primary electrical compatibility criterion.

Parameter Comparison

Engineering Selection Recommendations

Status Assessment:

The FQB2N90TM is classified as obsolete. The IRF540NSTRLPBF is classified as active with ROHS3 compliance and REACH unaffected status. However, direct substitution is not supported based on electrical parameters.

Voltage Rating Incompatibility:

The IRF540NSTRLPBF operates at a maximum drain-to-source voltage of 100V, which is insufficient for applications requiring 900V voltage withstand capability. Substituting this part in a 900V circuit will result in device failure and potential circuit damage.

Current and Thermal Performance:

While the IRF540NSTRLPBF exceeds the continuous drain current requirement (33A vs. 2.2A) and provides superior on-state resistance characteristics, these advantages are negated by the voltage rating mismatch.

Compliance and Availability:

The IRF540NSTRLPBF is currently in active production with 35,300 units in stock, compared to the FQB2N90TM with 949 units in stock (obsolete status). However, compliance and availability do not override electrical incompatibility.

Recommendation:

For applications currently using the FQB2N90TM, alternative high-voltage N-Channel MOSFETs rated for 900V or higher must be evaluated. The IRF540NSTRLPBF is not suitable for direct replacement in this application.

Frequently Asked Questions (FAQ)

Q: Can the IRF540NSTRLPBF replace the FQB2N90TM in my circuit?

A: No. The IRF540NSTRLPBF is rated for 100V maximum drain-to-source voltage, while the FQB2N90TM is rated for 900V. Using the IRF540NSTRLPBF in a 900V application will cause immediate device failure.

Q: Why is the voltage rating so different between these two parts?

A: The FQB2N90TM and IRF540NSTRLPBF are designed for fundamentally different application classes. The FQB2N90TM targets high-voltage switching applications, while the IRF540NSTRLPBF is optimized for lower-voltage, higher-current applications. They are not interchangeable.

Q: Are the packages compatible?

A: Yes, both devices use the Surface Mount TO-263 (D2PAK) package. However, package compatibility alone does not qualify a part as a substitute when electrical parameters are incompatible.

Q: What should I do since the FQB2N90TM is obsolete?

A: Identify alternative high-voltage N-Channel MOSFETs with 900V or higher Vdss rating, 2.2A or higher continuous drain current, and compatible gate drive characteristics. Consult the device datasheet and application circuit requirements to ensure full compatibility.

Q: Does the higher gate charge of the IRF540NSTRLPBF matter?

A: Gate charge differences become relevant only when comparing parts with compatible voltage and current ratings. In this case, the voltage incompatibility is the primary disqualifying factor.

Q: Can I use a higher-rated current device as a substitute?

A: Current rating alone does not determine substitutability. The voltage rating, on-state resistance, gate drive requirements, and thermal characteristics must all be compatible with the original application. The IRF540NSTRLPBF fails the voltage requirement regardless of its superior current rating.