MOSFET Selection for Medium-Voltage Power Applications: IRFU310PBF, IRFU110PBF vs. China Alternatives VBFB165R04, VBFB1102M
In medium-voltage power switching and conversion circuits, selecting a MOSFET that balances voltage rating, conduction loss, and cost is a key task for engineers. This is not merely a drop-in replacement exercise, but a careful consideration of performance, robustness, and supply chain options. This article takes two classic MOSFETs from VISHAY, the IRFU310PBF (400V) and IRFU110PBF (100V), as benchmarks. We will analyze their design cores and typical applications, and then evaluate two domestic alternative solutions, VBFB165R04 and VBFB1102M. By clarifying their parameter differences and performance orientations, we aim to provide a clear selection guide for your next power design.
Comparative Analysis: IRFU310PBF (400V N-channel) vs. VBFB165R04
Analysis of the Original Model (IRFU310PBF) Core:
This is a 400V N-channel MOSFET from VISHAY in a TO-251 (IPAK) package. As part of the third-generation Power MOSFET series, its design core is to offer a best combination of fast switching, ruggedness, low on-resistance (3.6Ω @10V), and cost-effectiveness for through-hole applications. It features a continuous drain current of 1.7A, making it suitable for medium-voltage, lower-current switching.
Compatibility and Differences of the Domestic Alternative (VBFB165R04):
VBsemi's VBFB165R04 is also offered in a TO-251 package, providing good pin-to-pin compatibility. The key differences are in the electrical parameters: VBFB165R04 has a significantly higher voltage rating (650V vs. 400V) and a much lower on-resistance (2200mΩ vs. 3600mΩ @10V). It also offers a higher continuous current rating of 4A.
Key Application Areas:
Original Model IRFU310PBF: Ideal for cost-sensitive, medium-voltage applications requiring ruggedness and through-hole mounting, such as offline switch-mode power supplies (SMPS) auxiliary circuits, lighting ballasts, or low-power AC-DC converters around 400V.
Alternative Model VBFB165R04: With its higher 650V rating and lower RDS(on), it is better suited for applications requiring a higher voltage safety margin or operating in 500-600V ranges, such as higher-power flyback converters, PFC stages, or industrial controls, while also offering improved conduction loss.
Comparative Analysis: IRFU110PBF (100V N-channel) vs. VBFB1102M
This comparison focuses on 100V-rated MOSFETs where the balance between on-resistance and current capability is critical for efficiency.
Analysis of the Original Model (IRFU110PBF) Core:
Also from VISHAY's third-generation series in a TO-251 package, the IRFU110PBF is designed for 100V applications. Its core advantages are a relatively low on-resistance of 540mΩ (@10V) and a continuous current rating of 4.3A, providing a reliable and cost-effective solution for various power switching tasks.
Compatibility and Differences of the Domestic Alternative (VBFB1102M):
VBsemi's VBFB1102M represents a significant "performance-enhanced" alternative. While maintaining the same 100V voltage rating and TO-251 package compatibility, it offers dramatically improved key parameters: a much lower on-resistance of 200mΩ (@10V) and a substantially higher continuous drain current of 12A.
Key Application Areas:
Original Model IRFU110PBF: A solid choice for general-purpose 100V switching where cost and proven ruggedness are priorities. Applications include DC-DC converters in 48V systems, motor drives for small appliances, and power management in industrial controls.
Alternative Model VBFB1102M: With its ultra-low RDS(on) and high current capability, it is an excellent upgrade for applications demanding higher efficiency and power density. It is well-suited for synchronous rectification in 48-100V DC-DC converters, more powerful motor drives, and any design where reducing conduction loss is paramount.
Conclusion:
This analysis reveals two distinct substitution strategies:
For 400V-class applications, the original IRFU310PBF offers a proven, cost-effective solution. Its domestic alternative VBFB165R04 provides a compelling option with a higher voltage rating (650V) and lower on-resistance, suitable for designs needing extra headroom or improved efficiency.
For 100V-class applications, the original IRFU110PBF is a reliable workhorse. However, the domestic alternative VBFB1102M delivers a substantial performance boost with significantly lower on-resistance and higher current capability, making it ideal for efficiency-critical upgrades.
The core takeaway is that selection depends on precise requirement matching. In the context of supply chain diversification, these domestic alternatives not only provide viable backup options but also offer performance advantages in key parameters, giving engineers greater flexibility and resilience in their design and cost optimization efforts. Understanding the specific demands of your circuit is essential to choosing the MOSFET that delivers maximum value.