MOSFET Selection for Medium/High Voltage Power Applications: STB18NF25, STW24N60M6 vs. China Alternatives VBL1252M, VBP16R15S
In the design of medium to high voltage power circuits, selecting a MOSFET that balances voltage rating, current capability, and switching efficiency is a critical task for engineers. This goes beyond simple part substitution, requiring careful consideration of performance, ruggedness, cost, and supply chain stability. This article takes two representative MOSFETs—STB18NF25 (250V) and STW24N60M6 (600V)—as benchmarks, analyzes their design focus and application scenarios, and evaluates their domestic alternative solutions, VBL1252M and VBP16R15S. By clarifying parameter differences and performance orientations, we aim to provide a clear selection guide to help you find the optimal power switching solution.
Comparative Analysis: STB18NF25 (250V N-Channel) vs. VBL1252M
Analysis of the Original Model (STB18NF25) Core:
This is an AEC-Q101 qualified, automotive-grade N-channel MOSFET from STMicroelectronics in a D2PAK (TO-263) package. Its design core is to provide robust and reliable performance in 250V applications. Key advantages include: a low on-resistance of 165mΩ at 10V gate drive, a continuous drain current rating of 17A, and low gate charge characteristic of the STripFET II technology, enabling efficient switching.
Compatibility and Differences of the Domestic Alternative (VBL1252M):
VBsemi's VBL1252M is offered in a compatible TO-263 package. The main differences are in electrical parameters: while both are 250V rated, VBL1252M has a slightly higher on-resistance (230mΩ @10V) and a marginally lower continuous current rating (16A) compared to the original.
Key Application Areas:
Original Model STB18NF25: Its automotive-grade ruggedness and balanced parameters make it suitable for demanding 250V circuits. Typical applications include:
Automotive systems: DC-DC converters, motor drives, and solenoid control.
Industrial power supplies: PFC stages, switch-mode power supplies (SMPS).
UPS and inverter systems.
Alternative Model VBL1252M: A viable alternative for industrial or consumer 250V applications where full automotive qualification is not mandatory, and the slight difference in RDS(on) and current is acceptable within the design margin.
Comparative Analysis: STW24N60M6 (600V N-Channel) vs. VBP16R15S
This comparison shifts to higher voltage domains, where the design pursuit is a balance of high voltage blocking, low conduction loss, and switching performance.
Analysis of the Original Model (STW24N60M6) Core:
This 600V N-channel MOSFET from ST uses the MDmesh M6 technology in a TO-247 package. Its core advantages are:
High Voltage & Low Resistance: A 600V drain-source rating paired with a typical on-resistance of 162mΩ (190mΩ max @10V).
Good Current Handling: A continuous current rating of 17A.
Advanced Technology: The MDmesh M6 structure offers improved switching performance and reduced gate charge.
Compatibility and Differences of the Domestic Alternative (VBP16R15S):
VBsemi's VBP16R15S is a pin-to-pin compatible alternative in a TO-247 package. It uses a Super Junction Multi-EPI process. The key differences are: a slightly higher specified on-resistance (280mΩ @10V) and a lower continuous current rating (15A) compared to the ST original.
Key Application Areas:
Original Model STW24N60M6: Ideal for high-efficiency, high-voltage power conversion. Typical applications include:
Server & Telecom SMPS: PFC and main switching stages.
Industrial motor drives: Inverters for 3-phase motors.
Solar inverters and energy storage systems.
Alternative Model VBP16R15S: Suitable as a cost-effective alternative in 600V applications where the design has sufficient margin for the higher RDS(on) and lower current rating, such as in certain industrial power supplies or lighting ballasts.
Conclusion:
This analysis outlines two distinct selection paths for medium and high-voltage applications:
For 250V automotive-grade or robust industrial applications, the original STB18NF25 offers a proven combination of 165mΩ RDS(on), 17A current, and AEC-Q101 qualification. Its domestic alternative VBL1252M provides a compatible package and similar voltage rating, serving as a viable option for cost-sensitive or supply-chain diversified designs where the parameter differences are acceptable.
For 600V high-power conversion applications, the original STW24N60M6 with its advanced MDmesh M6 technology offers excellent performance with low RDS(on) and 17A capability. The domestic alternative VBP16R15S presents a compatible, cost-competitive option for designs that can accommodate its specified 280mΩ RDS(on) and 15A rating.
The core takeaway is that selection hinges on precise requirement matching. In the context of supply chain diversification, domestic alternatives like VBL1252M and VBP16R15S not only provide feasible backup options but also offer engineers greater flexibility in design trade-offs and cost control. Understanding the specific parameter implications of each device is key to leveraging its full value in the circuit.