MOSFET Selection for High-Voltage Power Applications: STL15N65M5, STP28N60M2 vs. China Alternatives VBQA165R05S, VBM16R20
In today's high-voltage power designs, selecting a MOSFET that balances performance, reliability, and cost is a critical task for engineers. This goes beyond simple part substitution—it requires careful consideration of voltage rating, current capability, switching efficiency, and thermal management. This article takes two representative high-voltage MOSFETs, STL15N65M5 and STP28N60M2 from STMicroelectronics, as benchmarks. We will deeply analyze their design cores and application scenarios, and provide a comparative evaluation of two domestic alternative solutions: VBQA165R05S and VBM16R20 from VBsemi. By clarifying their parameter differences and performance orientations, we aim to offer a clear selection guide to help you find the most suitable power switching solution for your next high-voltage design.
Comparative Analysis: STL15N65M5 (N-channel) vs. VBQA165R05S
Analysis of the Original Model (STL15N65M5) Core:
This is a 650V N-channel MOSFET from STMicroelectronics, featuring the MDmesh M5 technology and housed in a compact PowerFLAT 5x6 HV (VDFN-8) package. Its design core focuses on achieving high-voltage switching with good efficiency in a space-saving format. Key advantages include a high drain-source voltage (Vdss) of 650V, a continuous drain current (Id) of 10A, and a typical on-resistance (RDS(on)) of 0.335 Ohm (375mΩ @10V). This makes it suitable for high-voltage, medium-current applications where board space is limited.
Compatibility and Differences of the Domestic Alternative (VBQA165R05S):
VBsemi's VBQA165R05S is also offered in a DFN8(5x6) package and serves as a pin-to-pin compatible alternative. The main differences lie in the electrical parameters: while it matches the 650V voltage rating, its continuous current rating is lower at 5A, and its on-resistance is higher at 1000mΩ @10V. This indicates the alternative is geared towards applications with lower current demands.
Key Application Areas:
Original Model STL15N65M5: Ideal for compact high-voltage circuits requiring a balance of voltage withstand and current capability. Typical applications include:
Auxiliary power supplies in industrial systems.
Power factor correction (PFC) stages in SMPS.
Lighting ballasts and LED drivers.
Alternative Model VBQA165R05S: More suitable for high-voltage applications where space is critical but current requirements are moderate (around 5A), such as in low-power auxiliary supplies or specific lighting controls.
Comparative Analysis: STP28N60M2 (N-channel) vs. VBM16R20
This comparison shifts to a higher-power domain, where the design pursuit is high current handling and low conduction loss in a robust package.
Analysis of the Original Model (STP28N60M2) Core:
This 600V N-channel MOSFET from ST uses MDmesh M2 technology in a standard TO-220-3 package. Its core advantages are:
High Current Capability: It supports a continuous drain current of 22A, suitable for substantial power levels.
Low On-Resistance: With an RDS(on) of 135mΩ @10V, it minimizes conduction losses.
Robust Package: The TO-220 package provides excellent thermal performance for power dissipation.
Compatibility and Differences of the Domestic Alternative (VBM16R20):
VBsemi's VBM16R20, also in a TO-220 package, presents a compelling "performance-comparable" alternative. It offers a similar 600V voltage rating and a high continuous current of 20A. Notably, its on-resistance is very competitive, specified at 128mΩ @4.5V and 160mΩ @10V, which is in the same range as the original part, promising similar conduction efficiency.
Key Application Areas:
Original Model STP28N60M2: Its combination of high voltage, high current, and low RDS(on) makes it a workhorse for demanding power conversion stages. Typical uses include:
Main switches in offline SMPS and UPS systems.
Motor drives and inverters for industrial equipment.
High-power PFC circuits.
Alternative Model VBM16R20: Serves as a strong direct replacement in most applications requiring a 600V / ~20A MOSFET with low conduction loss, such as switch-mode power supplies and motor controllers, offering a reliable domestic option.
Conclusion
In summary, this analysis reveals two distinct selection paths for high-voltage applications:
For compact, high-voltage (650V) designs where space is premium, the original STL15N65M5, with its 10A current and MDmesh M5 technology in a small package, is a strong choice for auxiliary power and lighting. Its domestic alternative VBQA165R05S provides package compatibility and the same voltage rating but is tailored for lower-current (5A) scenarios within similar form factors.
For high-power, high-current (600V) applications demanding robust performance, the original STP28N60M2 stands out with its 22A rating and low 135mΩ RDS(on) in a TO-220 package, making it suitable for main power stages. The domestic alternative VBM16R20 emerges as a highly competitive substitute, matching the voltage, offering a similar 20A current, and featuring a comparably low on-resistance, providing a viable and efficient alternative for cost-sensitive or supply-chain-diversified projects.
The core takeaway is that selection hinges on precise requirement matching. In the context of supply chain diversification, domestic alternatives like VBQA165R05S and VBM16R20 not only offer feasible backups but also provide engineers with greater flexibility in design trade-offs and cost control for high-voltage power solutions.