The rapid evolution of automotive electrification demands higher efficiency, greater power density, and enhanced reliability in low-to-medium voltage power systems. In this landscape, securing a robust, high-performance, and supply-chain-resilient alternative for core power switches is pivotal for automotive OEMs and Tier‑1 suppliers. Targeting the widely adopted 75V N‑channel MOSFET from Nexperia—the BUK7Y28-75B,115—the VBED1806 from VBsemi stands out as a superior replacement. It not only matches the functional footprint but achieves a significant leap in key performance metrics through advanced Trench technology, transitioning from a “direct substitute” to a “performance‑enhancing upgrade.”
I. Parameter Comparison & Performance Advantages: The Edge of Advanced Trench Technology
The BUK7Y28-75B,115 has been a reliable choice for automotive low-voltage switching applications due to its 75 V drain‑source voltage, 35.5 A continuous current, and 28 mΩ typical on‑resistance. However, evolving requirements for lower losses, higher current capability, and better thermal behavior call for a more capable solution.
1. Building on hardware compatibility with a similar LFPAK56 package and single N‑channel configuration, the VBED1806 delivers decisive improvements through optimized Trench architecture:
- Lower On‑Resistance: With VGS = 10 V, RDS(on) is just 6 mΩ – a reduction of nearly 80% compared to the reference part. This dramatically cuts conduction losses (Pcond = I_D²·RDS(on)) at high currents, improving efficiency and easing thermal management.
- Higher Current Handling: The continuous drain current rating reaches 90 A, more than doubling the original capability, enabling higher power throughput or greater design margin.
- Enhanced Voltage Margin: With a VDS of 80 V, the VBED1806 offers extra headroom for voltage spikes in 48 V automotive systems, improving robustness.
2. Optimized Switching Performance: The device exhibits lower gate charge (Qg) and output capacitance (Coss) compared to conventional counterparts, reducing switching losses and enabling higher‑frequency operation for more compact magnetic components.
3. Superior Thermal & Safe‑Operating‑Area (SOA) Performance: The advanced package and silicon design ensure excellent thermal dissipation, supporting sustained high‑current operation in demanding environments such as engine compartments or integrated powertrain modules.
II. Application Scenarios: From Pin‑to‑Pin Replacement to System‑Level Enhancement
The VBED1806 can directly replace the BUK7Y28-75B,115 in existing designs while enabling system‑level benefits:
1. 48 V Motor Drives (EPS, Cooling Fans, PTC Heaters)
Lower RDS(on) and higher current capability reduce losses, improve efficiency, and allow for more compact motor drive designs without sacrificing output power.
2. DC‑DC Converters (48 V to 12 V/5 V)
Enhanced switching performance supports higher conversion frequencies, shrinking inductor and transformer size. Reduced conduction loss boosts overall converter efficiency, critical for extended electric range.
3. Battery Management Systems (BMS) & Power Distribution
The high current rating and robust SOA make it suitable for high‑side switches in BMS or solid‑state relay replacements, ensuring reliable protection and distribution in 48 V battery systems.
4. Industrial & Consumer Power Supplies
Suitable for server power, telecom rectifiers, and industrial SMPS where high current, low loss, and high reliability are required.
III. Beyond Specifications: Supply Chain Security, Cost & Support
Selecting the VBED1806 is both a technical and strategic decision:
1. Domestic Supply Chain Assurance
VBsemi controls the full chain from chip design to packaging and testing, ensuring stable supply, shorter lead times, and resilience against geopolitical trade uncertainties.
2. Total Cost Advantage
With superior performance at a competitive price, the VBED1806 reduces BOM cost and offers better performance per dollar, enhancing end‑product competitiveness.
3. Localized Technical Support
Rapid response from selection guidance, simulation models, testing support, to failure analysis accelerates customer design cycles and problem resolution.
IV. Replacement Guidelines & Verification Steps
For designs currently using or considering the BUK7Y28-75B,115, the following steps are recommended:
1. Electrical Performance Validation
Compare switching waveforms, loss distribution, and temperature rise under same circuit conditions. Optimize gate drive parameters to leverage the VBED1806’s faster switching and lower gate charge.
2. Thermal & Mechanical Assessment
Due to significantly lower losses, heat sink requirements may be reduced. Verify layout compatibility and thermal performance in the target application.
3. Reliability & System-Level Testing
Perform rigorous electrical, thermal, and environmental stress tests, followed by vehicle‑level validation to ensure long‑term reliability under automotive operating conditions.
Driving the Future with Domestic Power Excellence
The VBsemi VBED1806 is not just a drop‑in alternative to the BUK7Y28-75B,115; it is a higher‑performance, higher‑current solution that enables efficiency gains, power density improvements, and enhanced system reliability. In an era of accelerating automotive electrification and supply chain localization, adopting the VBED1806 represents both a smart engineering upgrade and a strategic move toward supply chain autonomy. We confidently recommend this device and look forward to partnering with you to power the next generation of automotive electronics.