In medium-voltage power circuit design, selecting MOSFETs that balance voltage rating, current capability, and switching efficiency is a key task for engineers. This involves careful trade-offs among performance, reliability, and cost. This article uses two representative MOSFETs—SI7489DP-T1-GE3 (P-channel) and SI7898DP-T1-GE3 (N-channel)—as benchmarks, analyzes their design focus and application scenarios, and evaluates two domestic alternative solutions: VBQA2104N and VBGQA1156N. By clarifying parameter differences and performance orientations, we provide a clear selection guide to help you find the optimal power switching solution.
Comparative Analysis: SI7489DP-T1-GE3 (P-channel) vs. VBQA2104N
Analysis of the Original Model (SI7489DP-T1-GE3) Core:
This is a 100V P-channel MOSFET from Vishay in a PowerPAK SO-8 package. Its design focuses on robust performance in medium-voltage applications. Key advantages include a high continuous drain current of 28A and an on-resistance (RDS(on)) of 41mΩ at 10V gate drive. It is halogen-free per IEC 61249-2-21, making it suitable for environmentally sensitive designs. The TrenchFET technology ensures good switching characteristics and reliability.
Compatibility and Differences of the Domestic Alternative (VBQA2104N):
VBsemi’s VBQA2104N is offered in a compact DFN8 (5x6) package and serves as a functional alternative. Key parameter comparisons:
- Both are single P-channel, -100V Vdss, and rated for -28A continuous current.
- VBQA2104N features a lower on-resistance: 36mΩ at 4.5V and 32mΩ at 10V, compared to the original’s 41mΩ at 10V. This indicates potentially lower conduction losses.
- The alternative uses Trench technology, similar to the original’s TrenchFET, ensuring comparable switching performance.
Key Application Areas:
- Original Model SI7489DP-T1-GE3: Ideal for 48V-100V systems requiring high-side switching with good current handling, such as industrial power supplies, telecom DC-DC converters, and motor drive circuits.
- Alternative Model VBQA2104N: With lower on-resistance and a compact DFN package, it is suitable for space-constrained, high-efficiency applications in similar voltage ranges, offering an upgrade in conduction performance.
Comparative Analysis: SI7898DP-T1-GE3 (N-channel) vs. VBGQA1156N
Analysis of the Original Model (SI7898DP-T1-GE3) Core:
This is a 150V N-channel MOSFET in a PowerPAK SO-8 package. It is designed for medium-voltage switching with a balance of voltage withstand and current capability. Key parameters include a 150V drain-source voltage, 4.8A continuous current, and an on-resistance of 95mΩ at 6V gate drive (85mΩ at 10V). It provides reliable performance in applications requiring moderate current and high voltage.
Compatibility and Differences of the Domestic Alternative (VBGQA1156N):
VBsemi’s VBGQA1156N, in a DFN8 (5x6) package, offers significant performance enhancement:
- Both are single N-channel, 150V Vdss.
- VBGQA1156N boasts a much higher continuous current rating of 20A, compared to the original’s 4.8A.
- Its on-resistance is significantly lower at 56mΩ at 10V, versus the original’s 85mΩ at 10V.
- The alternative utilizes SGT (Shielded Gate Trench) technology, enabling faster switching and lower losses.
Key Application Areas:
- Original Model SI7898DP-T1-GE3: Suitable for medium-voltage, lower-current applications such as auxiliary power switches, LED drivers, or low-power motor controls in 100V-150V systems.
- Alternative Model VBGQA1156N: With its high current capability (20A) and low on-resistance, it is ideal for demanding applications like high-power DC-DC converters, motor drives, and industrial inverters where higher efficiency and power density are required.
Summary and Selection Guide
This analysis reveals two distinct selection paths:
For P-channel applications in the 100V range, the original SI7489DP-T1-GE3 offers a robust, halogen-free solution with 28A current capability, suitable for industrial and telecom power systems. The domestic alternative VBQA2104N provides a package-compatible option with lower on-resistance (32mΩ at 10V), making it an attractive choice for designs prioritizing efficiency and compact size.
For N-channel applications around 150V, the original SI7898DP-T1-GE3 serves well in lower-current (4.8A) scenarios. The domestic alternative VBGQA1156N delivers substantial performance uplift with 20A current rating and 56mΩ on-resistance, enabled by SGT technology. It is a superior choice for upgrades requiring higher power handling and reduced conduction losses.
Core Conclusion: Selection depends on precise requirement matching. In a diversified supply chain, domestic alternatives like VBQA2104N and VBGQA1156N not only provide reliable backups but also offer enhanced parameters in key areas, giving engineers greater flexibility in design trade-offs and cost optimization. Understanding each device’s design philosophy and parameter implications is essential to maximize circuit performance.