With the rapid advancement of precision agriculture and aerial application technology, Electric Vertical Take-Off and Landing (eVTOL) aircraft for plant protection have become core equipment for efficient and intelligent farming. The powertrain and power distribution systems, serving as the "heart and muscles" of the entire aircraft, provide precise power conversion and management for key loads such as propulsion motors, high-voltage battery systems, and auxiliary control units. The selection of power MOSFETs directly determines system efficiency, power density, thermal performance, and operational reliability. Addressing the stringent requirements of eVTOLs for high thrust-to-weight ratio, long endurance, safety, and robustness in harsh environments, this article focuses on scenario-based adaptation to develop a practical and optimized MOSFET selection strategy.
I. Core Selection Principles and Scenario Adaptation Logic
(A) Core Selection Principles: Four-Dimensional Collaborative Adaptation
MOSFET selection requires coordinated adaptation across four dimensions—voltage, loss, package, and reliability—ensuring precise matching with the demanding operating conditions of eVTOLs:
Sufficient Voltage Margin: For high-voltage battery buses (e.g., 400V, 600V), reserve a rated voltage withstand margin of ≥50% to handle voltage spikes during regenerative braking and transient conditions. For lower voltage auxiliary buses (e.g., 48V, 24V), similar margin rules apply.
Prioritize Ultra-Low Loss: Prioritize devices with extremely low Rds(on) to minimize conduction loss in high-current paths and low Qg/Coss to reduce switching loss at high frequencies. This is critical for maximizing motor efficiency, extending flight time, and managing thermal loads.
Package & Thermal Matching: Choose packages with excellent thermal performance (e.g., TO247, TO220, D2PAK) and low parasitic inductance for high-power propulsion inverters. Select compact, thermally enhanced packages (e.g., DFN, SOP8) for auxiliary power circuits, balancing power density, weight, and cooling requirements.
High Reliability & Ruggedness: Meet stringent reliability requirements for continuous vibration, wide ambient temperature ranges (-40°C to 125°C+), and potential moisture exposure. Focus on robust technology (SGT, Deep-Trench), high junction temperature capability, and strong avalanche ratings.
(B) Scenario Adaptation Logic: Categorization by Load Type
Divide loads into three core scenarios: First, Propulsion Motor Drive (Thrust Core), requiring very high current, ultra-low loss, and robust switching. Second, High-Voltage DC Link & Power Management (System Core), requiring high voltage blocking capability and good efficiency. Third, Auxiliary & Control System Power (Functional Support), requiring a balance of medium current, low loss, and compact size.
II. Detailed MOSFET Selection Scheme by Scenario
(A) Scenario 1: Propulsion Motor Drive Inverter (High Power) – Thrust Core Device
Multi-phase BLDC/PMSM motors for propulsion demand handling extreme continuous and peak currents (during take-off/climb) with utmost efficiency and reliability.
Recommended Model: VBGM1103 (N-MOS, 100V, 120A, TO220, SGT Tech)
Parameter Advantages: SGT technology achieves an ultra-low Rds(on) of 3.7mΩ at 10V. Continuous current of 120A (with high peak capability) suits high-current 48V or low-voltage 100V bus architectures. TO220 package offers excellent thermal dissipation capability when mounted properly.
Adaptation Value: Dramatically reduces conduction loss in the inverter phase legs. For a phase current of 80A, conduction loss per device is only ~23.7W, contributing to high inverter efficiency (>98%) crucial for flight time. The 100V rating provides good margin for 48V systems with transients.
Selection Notes: Must be used in multi-phase bridge configurations with dedicated motor driver ICs or controllers. Requires intensive thermal management with heatsinks. Verify worst-case peak current and junction temperature under climb/load scenarios. Parallel devices may be needed for higher power motors.
(B) Scenario 2: High-Voltage Battery System & DC-DC Conversion – System Core Device
Input stages, DC-link clamping, and high-voltage isolated DC-DC converters require devices with high voltage blocking capability and reasonable switching performance.
Recommended Model: VBP17R07 (N-MOS, 700V, 7A, TO247, Planar Tech)
Parameter Advantages: 700V drain-source voltage is ideal for direct use in 400V battery bus systems, offering ~75% margin to handle spikes. TO247 package provides the necessary creepage/clearance and thermal dissipation for such voltages. Avalanche ruggedness is typical for planar technology at this voltage.
Adaptation Value: Enables efficient design of PFC stages, DC-link active clamping circuits, or primary-side switches in high-voltage isolated DC-DC converters. Its voltage rating ensures system robustness against transients common in aerial vehicle power networks.
Selection Notes: The Rds(on) is relatively high (1.4Ω); thus, it is suited for positions where continuous current is moderate but voltage blocking is critical. Switching loss optimization is important. Requires gate drive circuits capable of handling higher voltage swings (±30V max).
(C) Scenario 3: Auxiliary System Power Switching & Low-Voltage Distribution – Functional Support Device
Auxiliary loads (flight controllers, servos, pumps, sensors, communication modules) require efficient power distribution, on/off control, and protection.
Recommended Model: VBA1810S (N-MOS, 80V, 13A, SOP8, Trench Tech)
Parameter Advantages: An excellent balance of voltage (80V), very low Rds(on) (10mΩ @10V), and current (13A) in a compact SOP8 package. Low Vth (1.7V) allows easy drive by 3.3V/5V logic. The 80V rating provides ample margin for 24V/48V auxiliary buses.
Adaptation Value: Perfect for high-side or low-side load switches controlling multiple auxiliary units. Its low loss minimizes voltage drop and heating in power distribution paths. The SOP8 package saves weight and board space, critical in aerospace applications.
Selection Notes: Ensure single-load current is adequately derated. For high-side switching, a suitable gate drive level-shifter or charge pump is needed. Provide sufficient PCB copper for heat dissipation from the SOP8 package.
III. System-Level Design Implementation Points
(A) Drive Circuit Design: Matching Device Characteristics
VBGM1103: Requires a high-current, low-impedance gate driver (e.g., 2A-4A peak) to achieve fast switching and minimize cross-conduction loss. Use Kelvin source connection if possible. Implement active Miller clamp or negative turn-off voltage for robustness.
VBP17R07: Gate drive must respect the ±30V Vgs limit. Use isolated or high-side gate drivers (e.g., based on SiC/GaN driver ICs) with proper UVLO. Snubber circuits may be necessary to manage voltage overshoot.
VBA1810S: Can often be driven directly by MCU GPIOs for slower switching, but for best efficiency, use a small MOSFET driver buffer. Include a gate series resistor (e.g., 10Ω-47Ω) to control slew rate and damp ringing.
(B) Thermal Management Design: Mission-Critical for eVTOL
VBGM1103 (Propulsion Inverter): Thermal management is paramount. Use insulated thermal pads to mount TO220 devices on a liquid-cooled cold plate or a large, forced-air-cooled heatsink. Monitor junction temperature via NTC or driver IC fault signals.
VBP17R07 (HV Power): Mount on a heatsink considering high-voltage isolation requirements. Thermal interface material must have appropriate dielectric strength.
VBA1810S (Auxiliary): Ensure the PCB has adequate copper pour (≥100mm²) connected to the thermal pad of the SOP8 package. Use thermal vias to inner layers or backside ground plane for heat spreading. In compact modules, consider ambient airflow.
(C) EMC and Reliability Assurance
EMC Suppression:
VBGM1103: Minimize high di/dt and dv/dt loops in the inverter layout. Use low-ESR/ESL DC-link capacitors. Consider RC snubbers across each switch or phase output.
VBP17R07: Use ferrite beads in gate drive paths and add small film capacitors across drain-source to filter high-frequency noise.
Implement strict zoning: keep high-power motor loops, high-voltage sections, and sensitive analog/digital control areas separate.
Reliability Protection:
Derating: Apply conservative derating (e.g., voltage ≤80% of rating, current derated based on max estimated junction temperature).
Overcurrent/SOAP Protection: Use shunt resistors or desaturation detection integrated in motor drivers (for VBGM1103). Implement fuse or e-fuse protection for auxiliary branches (using VBA1810S).
Voltage Transient Protection: Place TVS diodes or varistors at battery inputs, motor terminals, and auxiliary power inputs. Ensure gate-source protection with Zener diodes or TVS for all MOSFETs.
IV. Scheme Core Value and Optimization Suggestions
(A) Core Value
Maximized Powertrain Efficiency: Ultra-low loss devices in the propulsion chain directly increase thrust efficiency and flight endurance.
System-Level Robustness: Combination of high-voltage rugged devices and highly efficient low-voltage switches ensures reliable operation under the stressful and variable conditions of agricultural flight.
Optimal Weight & Performance Balance: Selected packages offer the best thermal and electrical performance per gram, a critical metric for eVTOL design.
(B) Optimization Suggestions
Higher Power Propulsion: For higher voltage (e.g., 600V+) or higher power motor drives, consider SJ_Multi-EPI technology devices like VBPB15R14S (500V/14A) in TO3P package, or evaluate SJ_Deep-Trench devices like VBFB165R05SE (650V/5A) for specific converter topologies.
Extreme Current Auxiliary Loads: For very high current auxiliary distribution (e.g., heater pads, powerful servos), the VBMB1302A (30V/180A, TO220F) offers an exceptional current density.
High-Side Switching Simplification: For 48V-60V high-side switches where P-channel simplification is desired, consider VBL2606 (P-MOS, -60V, -120A, TO263) for minimal conduction loss.
Integration Path: For propulsion inverters, future designs should evaluate integrated power modules (IPMs) or custom power stages built around these discrete devices for further size and weight reduction.
Conclusion
Power MOSFET selection is central to achieving the high efficiency, reliability, and power density required for successful agricultural plant protection eVTOLs. This scenario-based scheme, leveraging devices optimized for propulsion, high-voltage handling, and auxiliary control, provides comprehensive technical guidance for R&D through precise load matching and system-level design. Continuous exploration of Wide Bandgap (SiC, GaN) devices and advanced packaging will further aid in developing the next generation of high-performance, long-endurance aerial application platforms, solidifying their role in modern precision agriculture.

Detailed Topology Diagrams