FQB2N50TM Equivalent & Substitute Parts

Part Overview

The FQB2N50TM is an N-Channel MOSFET manufactured by onsemi, rated for 500V drain-to-source voltage with 2.1A continuous drain current. The device is packaged in a Surface Mount TO-263 (D2PAK) configuration and is classified as obsolete. Due to its obsolete status, equivalent and substitute parts are necessary to maintain design continuity and ensure component availability for new production runs and field replacements.

Substiute Parts

FQB2N50TM

onsemiIn Stock: 1193FQB2N50TM Datasheet

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IRF540NSTRLPBF

Infineon TechnologiesIn Stock: 35365IRF540NSTRLPBF Datasheet

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IRFI820GPBF

Vishay SiliconixIn Stock: 16414IRFI820GPBF Datasheet

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IXTA08N50D2

IXYSIn Stock: 1161IXTA08N50D2 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the FQB2N50TM is determined by the following critical parameters:

Voltage Rating (Vdss): The substitute must support 500V or higher drain-to-source voltage to maintain circuit protection and reliability margins.

Current Rating (Id): The substitute must support 2.1A or higher continuous drain current at 25°C to handle the design load without thermal stress.

On-State Resistance (Rds On): The substitute must maintain comparable or lower on-state resistance to ensure similar power dissipation and thermal performance.

Gate Threshold Voltage (Vgs(th)): The substitute must have compatible gate threshold voltage to ensure proper gate drive compatibility.

Operating Temperature Range: The substitute must support the -55°C to 150°C operating range or wider.

Mounting Type and Package: Surface Mount TO-263 (D2PAK) packaging is preferred for direct replacement; however, through-hole alternatives may be considered for applications where board layout permits.

The three substitute parts listed below meet these criteria with varying trade-offs in current capacity, power dissipation, and packaging configuration.

Parameter Comparison

Engineering Selection Recommendations

IRFI820GPBF (Vishay Siliconix): This part provides the closest electrical match to the FQB2N50TM, with identical 500V voltage rating and 2.1A current rating. The lower on-state resistance (3Ohm vs. 5.3Ohm) provides improved thermal performance. However, the package is through-hole TO-220-3 rather than surface mount, requiring board layout modification. The part is active and ROHS3 compliant, ensuring long-term availability and regulatory compliance.

IRF540NSTRLPBF (Infineon Technologies): This part offers significantly higher current capacity (33A) and power dissipation (130W), making it suitable for applications requiring higher current handling. However, the 100V voltage rating is insufficient for 500V applications and disqualifies this part as a direct substitute. This part is active and suitable only for lower-voltage circuit variants.

IXTA08N50D2 (IXYS): This part maintains the 500V voltage rating and surface mount TO-263 packaging, providing direct board compatibility. However, the 800mA current rating is below the 2.1A requirement of the original design, limiting its use to lower-current applications. The part is active and ROHS3 compliant. The depletion-mode FET feature differs from the enhancement-mode FQB2N50TM, requiring gate drive circuit evaluation.

Primary Recommendation: IRFI820GPBF is the most suitable substitute when board layout permits through-hole mounting, offering superior electrical performance and active product status. For surface mount applications requiring 500V/2.1A performance, no direct equivalent exists among the listed substitutes.

Frequently Asked Questions (FAQ)

Q: Can IRF540NSTRLPBF replace FQB2N50TM in a 500V circuit?

A: No. The IRF540NSTRLPBF has a maximum Vdss rating of 100V, which is insufficient for 500V applications. Using this part in a 500V circuit will result in device failure and potential circuit damage.

Q: What is the primary difference between IRFI820GPBF and FQB2N50TM?

A: The electrical specifications are nearly identical (500V, 2.1A), with IRFI820GPBF offering lower on-state resistance (3Ohm vs. 5.3Ohm). The primary difference is packaging: IRFI820GPBF uses through-hole TO-220-3, while FQB2N50TM uses surface mount TO-263 (D2PAK). Board layout modification is required for substitution.

Q: Is IXTA08N50D2 suitable for applications requiring 2.1A continuous current?

A: No. IXTA08N50D2 is rated for 800mA maximum continuous drain current, which is below the 2.1A requirement. Using this part in a 2.1A application will cause thermal stress and potential device failure.

Q: Why is FQB2N50TM classified as obsolete?

A: The FQB2N50TM is listed as obsolete by onsemi, indicating it is no longer in active production. Substitute parts must be identified to ensure design continuity and component availability for future production runs.

Q: Are all substitute parts ROHS3 compliant?

A: IRFI820GPBF and IXTA08N50D2 are explicitly ROHS3 compliant. IRF540NSTRLPBF RoHS status is not specified in the provided data. Compliance verification with the component supplier is recommended for regulatory applications.

Q: What is the significance of gate charge (Qg) differences between parts?

A: Gate charge affects gate drive circuit design and switching speed. IRFI820GPBF has higher gate charge (24nC vs. 8nC), requiring higher gate drive current or longer switching times. This may impact circuit performance in high-frequency applications.

Q: Can IXTA08N50D2 be used as a direct board replacement for FQB2N50TM?

A: IXTA08N50D2 uses the same surface mount TO-263 package, allowing direct board replacement from a mechanical standpoint. However, the 800mA current rating and depletion-mode operation disqualify it for applications requiring 2.1A enhancement-mode performance.

Q: What is the operating temperature range compatibility?

A: FQB2N50TM, IRFI820GPBF, and IXTA08N50D2 all support -55°C to 150°C operation. IRF540NSTRLPBF extends to 175°C, providing wider temperature margin. All parts are suitable for standard industrial temperature ranges.