MOSFET Selection for High-Voltage Power Applications: STP35N60DM2, STF33N60DM6 vs. China Alternatives VBM165R25S, VBMB16R26S
In high-voltage power conversion and motor drive designs, selecting a MOSFET that balances ruggedness, efficiency, and cost is a critical engineering decision. This goes beyond simple cross-referencing; it involves a careful trade-off among voltage rating, conduction loss, switching performance, and thermal management. This article takes two representative high-voltage MOSFETs from STMicroelectronics—STP35N60DM2 (TO-220) and STF33N60DM6 (TO-220FP)—as benchmarks. We will analyze their design cores and application scenarios, then evaluate the two domestic alternative solutions, VBM165R25S and VBMB16R26S. By clarifying parameter differences and performance orientations, we aim to provide a clear selection guide to help you find the optimal power switching solution in your next high-voltage design.
Comparative Analysis: STP35N60DM2 (TO-220) vs. VBM165R25S
Analysis of the Original Model (STP35N60DM2) Core:
This is a 600V N-channel MOSFET from STMicroelectronics, featuring the MDmesh DM2 technology in a standard TO-220 package. Its design core is to deliver robust performance and high efficiency in high-voltage applications. Key advantages include: a high voltage rating of 600V, a continuous drain current of 28A, and a low typical on-resistance (RDS(on)) of 94mΩ (110mΩ @ 10V per datasheet). The TO-220 package offers excellent thermal dissipation for medium-to-high power levels.
Compatibility and Differences of the Domestic Alternative (VBM165R25S):
VBsemi's VBM165R25S is a direct pin-to-pin compatible alternative in the TO-220 package. The main differences lie in the electrical parameters: VBM165R25S offers a slightly higher voltage rating (650V vs. 600V) and features a Super Junction Multi-EPI structure. Its on-resistance is comparable at 115mΩ @ 10V, while the continuous current rating is 25A.
Key Application Areas:
Original Model STP35N60DM2: Its combination of 600V rating, 28A current capability, and low RDS(on) makes it ideal for high-efficiency, medium-power off-line applications. Typical uses include:
Switch-Mode Power Supplies (SMPS): PFC stages, flyback, or forward converters in AC-DC power supplies.
Motor Drives: Inverter stages for driving induction motors or BLDC motors in appliances and industrial controls.
Lighting: High-voltage ballasts and LED driving circuits.
Alternative Model VBM165R25S: Suitable as a robust alternative in similar 600V-650V applications where the 25A current capability is sufficient, offering a reliable domestic option with comparable conduction loss.
Comparative Analysis: STF33N60DM6 (TO-220FP) vs. VBMB16R26S
This comparison focuses on high-voltage MOSFETs in the TO-220FP (fully isolated) package, where thermal performance and isolation are key.
Analysis of the Original Model (STF33N60DM6) Core:
This N-channel MOSFET utilizes ST's advanced MDmesh DM6 technology in a TO-220FP package. Its design pursues an optimal balance of low switching loss, low conduction loss, and enhanced thermal performance thanks to the isolated package. Key advantages are: a 600V voltage rating, 25A continuous current, and a low RDS(on) of 115mΩ @ 10V. The DM6 technology is optimized for high-frequency switching.
Compatibility and Differences of the Domestic Alternative (VBMB16R26S):
VBsemi's VBMB16R26S is a direct pin-to-pin compatible alternative in the TO-220FP package. It presents a compelling "performance-matched" option: it matches the 600V rating, offers a slightly higher continuous current of 26A, and maintains a very similar on-resistance of 115mΩ @ 10V. It also employs a Super Junction Multi-EPI process.
Key Application Areas:
Original Model STF33N60DM6: Its low RDS(on), fast switching characteristics (benefiting from DM6 technology), and isolated package make it excellent for applications requiring high efficiency and reliable thermal management without an external insulator. Typical uses include:
High-Frequency SMPS: Particularly in LLC resonant converters and advanced topologies.
Industrial Motor Drives: Where isolation simplifies heatsink mounting.
Solar Inverters and UPS Systems: In the power stage for efficient energy conversion.
Alternative Model VBMB16R26S: Serves as a highly suitable alternative for applications currently using the STF33N60DM6, offering equivalent electrical performance and package benefits, making it a strong candidate for design-in or replacement to enhance supply chain diversity.
Conclusion
In summary, this analysis reveals clear and viable alternative paths for high-voltage MOSFETs:
For standard TO-220 package applications, the original STP35N60DM2, with its 28A current and low RDS(on), is a strong performer in medium-power SMPS and motor drives. Its domestic alternative VBM165R25S provides a compatible solution with a marginally higher voltage rating (650V) and a solid 25A/115mΩ performance, making it a practical alternative for many 600V-system designs.
For designs utilizing the isolated TO-220FP package, the original STF33N60DM6 offers excellent switching performance and thermal convenience. The domestic alternative VBMB16R26S emerges as a near-drop-in replacement, matching the 600V rating and 115mΩ RDS(on) while even offering a slightly higher 26A current rating, presenting a compelling alternative for efficiency-critical and thermally constrained applications.
The core takeaway is that selection is driven by precise application requirements. In the context of supply chain diversification, these domestic alternatives (VBM165R25S and VBMB16R26S) provide not only feasible backup options but also competitive performance, offering engineers greater flexibility and resilience in their design choices and cost optimization strategies. Understanding the specific demands of your voltage, current, thermal, and switching landscape is key to leveraging the full value of these components.