MOSFET Selection for Power Switching Solutions: IRF520, RFG50N05 vs. Domestic Alternatives VBM1101M, VBP1606
In power design, choosing the right MOSFET for switching and control applications involves balancing voltage, current, on-resistance, and package. This article takes two classic N-channel MOSFETs—IRF520 (TO-220) and RFG50N05 (TO-247)—as benchmarks, analyzes their design focus and typical use cases, and evaluates two domestic alternative solutions, VBM1101M and VBP1606. By comparing parameter differences and performance orientations, we provide a clear selection guide to help you find the most suitable power switch for your next project.
Comparative Analysis: IRF520 (N-channel) vs. VBM1101M
Analysis of the Original Model (IRF520) Core:
This is a 100V N-channel MOSFET from TI in a TO-220AB package. It is designed for general-purpose medium-power switching. Key features include a drain-source voltage (Vdss) of 100V, a continuous drain current (Id) of 9.2A, and an on-resistance (RDS(on)) of 270mΩ at 10V gate drive. Its robust TO-220 package offers good thermal performance for applications requiring moderate current handling and high voltage blocking.
Compatibility and Differences of the Domestic Alternative (VBM1101M):
VBsemi’s VBM1101M is also offered in a TO-220 package and serves as a pin-to-pin compatible alternative. The key differences are in electrical parameters: VBM1101M maintains the same 100V voltage rating but significantly improves continuous current to 18A and reduces on-resistance to 127mΩ at 10V. This results in lower conduction losses and higher current capability compared to the original IRF520.
Key Application Areas:
Original Model IRF520: Suitable for general-purpose switching, relay drivers, motor control, and power management in industrial, automotive, and consumer electronics where 100V blocking and ~9A current are sufficient.
Alternative Model VBM1101M: Ideal for upgrades requiring higher current (up to 18A) and lower conduction loss in similar 100V applications, such as enhanced motor drives, power supplies, or switching circuits demanding better efficiency.
Comparative Analysis: RFG50N05 (N-channel) vs. VBP1606
Analysis of the Original Model (RFG50N05) Core:
This TI MOSFET in a TO-247 package targets higher-current applications. It features a 50V drain-source voltage (Vdss), a continuous drain current (Id) of 50A, and a low on-resistance of 22mΩ at 10V. The TO-247 package provides excellent thermal dissipation, making it suitable for high-power switching.
Compatibility and Differences of the Domestic Alternative (VBP1606):
VBsemi’s VBP1606 is also housed in a TO-247 package and offers a performance-enhanced alternative. It has a slightly higher voltage rating of 60V, a much higher continuous current of 150A, and a dramatically lower on-resistance of 7mΩ at 10V. This makes it superior in reducing power loss and handling higher currents.
Key Application Areas:
Original Model RFG50N05: Fits high-current applications such as DC-DC converters, motor drives, power tools, and inverter circuits in 12V–48V systems where 50A current and 50V blocking are required.
Alternative Model VBP1606: Suited for demanding high-power applications like high-current motor drives, server power supplies, industrial inverters, and any design needing ultra-low RDS(on) (7mΩ) and very high current capability (150A) with a 60V rating.
Conclusion
This comparison highlights two distinct selection paths:
For general-purpose 100V N-channel switching in a TO-220 package, the original IRF520 provides reliable performance for up to 9.2A applications. Its domestic alternative VBM1101M offers a compatible upgrade with higher current (18A) and lower on-resistance (127mΩ), making it a compelling choice for improved efficiency and current handling.
For high-power 50V–60V N-channel applications in a TO-247 package, the original RFG50N05 delivers solid performance with 50A current and 22mΩ on-resistance. The domestic alternative VBP1606 significantly enhances key parameters—150A current and 7mΩ on-resistance—enabling higher power density and lower losses for the most demanding circuits.
The core takeaway: Selection depends on precise requirement matching. Domestic alternatives like VBM1101M and VBP1606 not only provide solid compatibility but also offer performance advantages in current and on-resistance, giving engineers flexible, cost-effective options for design optimization and supply chain resilience. Understanding each device’s parameters ensures you extract maximum value in your power switching solution.