With the rapid advancement of the urban air mobility (UAM) sector, all-electric Vertical Take-Off and Landing (eVTOL) flying cars demand extreme reliability, safety, and power density from their powertrains. The power MOSFETs, serving as the core switches for propulsion motor drives, battery management systems (BMS), and critical flight control loads, directly determine the system's efficiency, thermal performance, electromagnetic compatibility (EMC), and, most critically, operational safety and fault tolerance. Focusing on the stringent requirements of eVTOLs for high power, redundancy, and harsh-environment operation, this article reconstructs the MOSFET selection logic based on scenario adaptation, providing an optimized solution ready for direct implementation.
I. Core Selection Principles and Scenario Adaptation Logic
Core Selection Principles
Ultra-High Reliability & Redundancy: Devices must be rated for continuous operation under high vibration and wide temperature ranges. Electrical ratings must include significant safety margins (≥100% voltage derating recommended) to handle transients and ensure fail-operational or fail-safe capabilities.
Maximized Efficiency & Power Density: Prioritize devices with ultra-low on-state resistance (Rds(on)) and optimized gate charge (Qg) to minimize conduction and switching losses, crucial for maximizing flight time and battery life.
Robust Package and Thermal Performance: Select packages (TO-220, TO-247, TO-252) capable of withstanding high thermal stress and enabling efficient heat sinking via baseplates or liquid cooling, essential for peak power phases like takeoff and climb.
System-Level Safety Integration: Devices must facilitate the implementation of redundant power paths, isolation control, and comprehensive protection features (over-current, over-temperature, shoot-through prevention).
Scenario Adaptation Logic
Based on the critical load types within an eVTOL powertrain, MOSFET applications are divided into three primary scenarios: High-Power Propulsion Motor Drive, Battery System & High-Side Protection, and Critical Flight Control Loads. Device parameters and characteristics are matched accordingly to balance performance, safety, and integration.
II. MOSFET Selection Solutions by Scenario
Scenario 1: High-Power Propulsion Motor Drive (Multi-kW Range) – Power Core Device
Recommended Model: VBGM1252N (Single N-MOS, 250V, 80A, TO-220)
Key Parameter Advantages: Utilizes SGT (Shielded Gate Trench) technology, achieving an excellent balance of high voltage (250V) and low Rds(on) of 16mΩ at 10V gate drive. The 80A continuous current rating is suitable for phases of high-voltage (e.g., 400-800V bus) motor inverters.
Scenario Adaptation Value: The TO-220 package offers robust mechanical structure and excellent thermal interface capability for dedicated heatsinks or cold plates. The high voltage rating provides ample margin for bus voltages, ensuring resilience against regenerative braking spikes. Low conduction loss is critical for maintaining high system efficiency during sustained cruise.
Scenario 2: Battery System & High-Side Protection – Safety & Management Device
Recommended Model: VBE2605 (Single P-MOS, -60V, -140A, TO-252)
Key Parameter Advantages: Features an exceptionally low Rds(on) of 4mΩ (at 10V) combined with a very high continuous current rating of -140A. The -60V rating is well-suited for high-current 48V or lower-voltage auxiliary battery systems.
Scenario Adaptation Value: As a P-Channel MOSFET, it enables simple high-side switching for battery isolation, load disconnect, or redundant power path control without requiring complex gate drive level-shifting circuits. The ultra-low Rds(on) minimizes voltage drop and power loss in critical current paths, enhancing overall energy availability. The TO-252 (D2PAK) package provides a good balance of power handling and footprint.
Scenario 3: Critical Flight Control Loads – Redundant & High-Reliability Device
Recommended Model: VB9220 (Dual N+N MOS, 20V, 6A per Ch, SOT23-6)
Key Parameter Advantages: Integrates two matched N-MOSFETs in a miniaturized SOT23-6 package. Features a low gate threshold voltage (Vth: 0.5-1.5V), enabling direct drive from 3.3V/5V flight control computers (FCCs). Rds(on) is as low as 24mΩ at 4.5V gate drive.
Scenario Adaptation Value: The dual independent channels in a tiny footprint are ideal for constructing redundant control switches for critical avionics, sensors, actuators, or communication modules. Low Vth ensures reliable switching even with low-voltage logic. The integrated design saves significant PCB space in densely packaged flight control units while improving signal integrity and reliability over discrete solutions.
III. System-Level Design Implementation Points
Drive Circuit Design
VBGM1252N: Requires a dedicated, rugged gate driver IC with sufficient peak current capability. Implement reinforced isolation for motor drive stages. Focus on minimizing power loop inductance to suppress voltage spikes.
VBE2605: Can be driven via a simple bipolar transistor or small MOSFET level shifter. Incorporate active pull-down for fast, safe turn-off. Implement redundant gate control signals if used for critical battery isolation.
VB9220: Can be driven directly by FCC GPIO pins. Include series gate resistors and local bypass capacitors. Consider using both channels in parallel for higher current capability or independently for redundant control of a single load.
Thermal Management Design
Aggressive Cooling Strategy: VBGM1252N must be mounted on a high-performance heatsink, potentially with liquid cooling for multi-kW drives. VBE2605 requires substantial PCB copper pour or a dedicated heatsink based on current load. VB9220 relies on PCB thermal relief but its low power dissipation minimizes thermal stress.
Conservative Derating: Apply significant derating (e.g., 50% of rated current) for continuous operation at maximum rated junction temperature. Design thermal systems to maintain Tj well below maximum under all flight profiles (takeoff, cruise, landing).
EMC and Reliability Assurance
EMI Suppression: Utilize snubber circuits and optimized layout for motor drive stages (VBGM1252N). Employ ferrite beads and filtering for sensitive control lines driving VB9220.
Protection & Redundancy: Implement comprehensive fault detection (desaturation, overcurrent, overtemperature) for all high-power switches. Use TVS diodes and RC snubbers for surge protection. Design critical power paths with the VB9220 to allow for hot-swapping or load shedding in fault conditions.
IV. Core Value of the Solution and Optimization Suggestions
The power MOSFET selection solution for eVTOLs, based on scenario adaptation logic, provides a robust foundation for developing safe, efficient, and reliable aerial vehicles. Its core value is mainly reflected in the following three aspects:
Enhanced Safety and Fault Tolerance: By selecting devices like the high-side P-MOS (VBE2605) for battery management and the dual-channel N-MOS (VB9220) for critical loads, the solution inherently supports the design of redundant and isolated power paths. This is paramount for achieving fail-operational or fail-safe capabilities, directly contributing to the vehicle's airworthiness.
Optimized Power-to-Weight Ratio: The use of high-efficiency, low-loss MOSFETs like the VBGM1252N (SGT) and VBE2605 (Ultra-low Rds(on)) minimizes wasted energy as heat. This translates directly into extended range or reduced battery weight. Efficient thermal design enabled by robust packages further supports high power density.
Balanced Performance and System Integration: The solution covers the full spectrum from kW-level propulsion to watt-level control, using packages that facilitate effective thermal management and PCB layout. The integration of dual MOSFETs (VB9220) saves space and simplifies design for flight controllers, allowing engineers to focus on higher-level system integration and software development.
In the design of eVTOL powertrains and power distribution systems, MOSFET selection is a critical determinant of performance, safety, and certification viability. The scenario-based selection solution proposed in this article, by matching device capabilities to the specific demands of propulsion, battery safety, and flight-critical controls, provides a comprehensive, actionable technical roadmap. As eVTOLs evolve towards higher voltages, greater power, and more stringent safety standards, future exploration should focus on the application of next-generation wide-bandgap devices (SiC, GaN) for ultra-high efficiency and frequency, as well as the development of intelligent, condition-monitoring power modules. This will lay the solid hardware foundation required for the commercialization of safe, reliable, and high-performance flying cars, defining the future of urban transportation.

Detailed System Topology Diagrams