Driven by the rapid growth of food delivery and service robotics, smart delivery robots have become crucial for automated logistics. Their power supply and motor drive systems, serving as the "heart and muscles" of the entire unit, require precise, efficient, and robust power conversion and control for critical loads such as drive motors, computing units, sensors, and safety modules. The selection of power MOSFETs directly determines the system's efficiency, thermal performance, power density, and operational reliability in dynamic environments. Addressing the stringent demands of delivery robots for mobility, safety, endurance, and integration, this article centers on scenario-based adaptation to reconstruct the power MOSFET selection logic, providing an optimized solution ready for direct implementation.
I. Core Selection Principles and Scenario Adaptation Logic
Core Selection Principles
High Voltage & Current Ruggedness: For motor drives (typically 24V/48V) and safety circuits, MOSFETs must have ample voltage margins (>60V for 24V systems) and high current ratings to handle start-up surges, regenerative braking, and load variations.
Ultra-Low Loss for Endurance: Prioritize devices with minimal on-state resistance (Rds(on)) and gate charge (Qg) to maximize battery life by reducing conduction and switching losses.
Compact & Thermally Efficient Packaging: Select packages like DFN, TSSOP, SOT to meet space constraints in mobile platforms while ensuring excellent thermal performance for heat dissipation.
High Reliability under Harsh Conditions: Devices must withstand vibration, temperature fluctuations, and continuous operation, featuring robust ESD protection and stable parameters.
Scenario Adaptation Logic
Based on core load types within a delivery robot, MOSFET applications are divided into three primary scenarios: Drive Motor Control (Mobility Core), Centralized Power Distribution (System Power Hub), and Safety & Auxiliary Control (Functional Safety). Device parameters and characteristics are matched accordingly.
II. MOSFET Selection Solutions by Scenario
Scenario 1: Drive Motor Control (150W-400W) – Mobility Core Device
Recommended Model: VBGQF1810 (Single N-MOS, 80V, 51A, DFN8(3x3))
Key Parameter Advantages: Utilizes advanced SGT (Shielded Gate Trench) technology, achieving an ultra-low Rds(on) of 9.5mΩ at 10V Vgs. The high 80V VDS rating provides strong margin for 24V/48V bus systems, handling voltage spikes during braking. A continuous current rating of 51A meets the demands of high-torque wheel motors.
Scenario Adaptation Value: The DFN8 package offers very low thermal resistance and parasitic inductance, enabling compact, high-power-density motor drive inverter design. Ultra-low conduction loss minimizes heat generation in the drive stage, directly contributing to extended battery life and reduced cooling burden. Excellent switching performance supports high-frequency PWM for smooth and quiet motor operation.
Applicable Scenarios: Main drive motor H-bridge/inverter circuits, precise speed and torque control for wheel motors.
Scenario 2: Centralized Power Distribution – System Power Hub Device
Recommended Model: VBC1307 (Single N-MOS, 30V, 10A, TSSOP8)
Key Parameter Advantages: Features an extremely low Rds(on) of 7mΩ at 10V Vgs. A 30V rating is ideal for 12V/24V auxiliary power rails. The 10A current capability is sufficient for distributing power to multiple sub-systems.
Scenario Adaptation Value: The TSSOP8 package provides a good balance of size and thermal performance, easily managed via PCB copper pour. Its very low Rds(on) ensures minimal voltage drop and power loss on critical power paths. Suitable for intelligent power sequencing and load switching for computing units (e.g., ROS master), sensor clusters (LiDAR, cameras), and communication modules.
Applicable Scenarios: Main power rail switching, load switch for high-power subsystems, synchronous rectification in onboard DC-DC converters.
Scenario 3: Safety & Auxiliary Control – Functional Safety Device
Recommended Model: VB5610N (Dual N+P MOSFET, ±60V, ±4A, SOT23-6)
Key Parameter Advantages: Integrates a complementary N-MOS and P-MOS in one ultra-compact SOT23-6 package. High ±60V VDS rating offers robust protection for 24V systems. Symmetrical Vth and Rds(on) characteristics simplify circuit design.
Scenario Adaptation Value: The complementary pair enables elegant high-side (P-MOS) and low-side (N-MOS) switching solutions within minimal space. Perfect for implementing safe Emergency Stop (E-Stop) circuits, enabling/disabling peripheral modules (lights, speakers), and bidirectional load control. Provides functional isolation, allowing critical safety circuits to be controlled independently from the main logic.
Applicable Scenarios: E-Stop power cutoff control, enable/disable switches for safety sensors and alarms, compact H-bridge for small actuators or locking mechanisms.
III. System-Level Design Implementation Points
Drive Circuit Design
VBGQF1810: Pair with a robust three-phase motor driver IC. Ensure gate drive capability to handle its Qg efficiently. Minimize power loop inductance in PCB layout.
VBC1307: Can be driven directly by a microcontroller GPIO or power management IC. A small gate resistor is recommended.
VB5610N: The N-channel can be driven directly by MCU GPIO for low-side switching. For high-side P-channel control, use a simple level-shifter (NPN transistor or small N-MOS).
Thermal Management Design
Graded Heat Dissipation Strategy: VBGQF1810 requires a significant PCB copper pour area, potentially coupled to the chassis. VBC1307 benefits from copper pours on its TSSOP8 thermal pad. VB5610N's low power dissipation is manageable with standard layout practices.
Derating for Mobility: Apply conservative derating (e.g., 60-70% of rated current) to account for potential high ambient temperatures inside the robot enclosure and continuous operation.
EMC and Reliability Assurance
Motor EMI Suppression: Use snubber circuits or parallel capacitors across the motor terminals and VBGQF1810 drain-source to suppress voltage spikes and reduce EMI from the motor windings.
Transient Protection: Implement TVS diodes on all power input lines and near MOSFET drains exposed to long wires (e.g., motor leads). Ensure proper ESD protection on control signal lines.
Fault Protection: Integrate current sensing and fuse protection in motor drive and main power paths. Utilize the VB5610N in E-Stop loops to provide a reliable, software-independent hardware cutoff.
IV. Core Value of the Solution and Optimization Suggestions
The power MOSFET selection solution for smart delivery robots, based on scenario adaptation logic, achieves comprehensive coverage from core propulsion to power management and functional safety. Its core value is reflected in:
Full-Chain Energy Efficiency for Maximum Endurance: By selecting ultra-low Rds(on) MOSFETs like VBGQF1810 and VBC1307 for high-power paths, conduction losses are minimized across the system. This directly translates to extended operational range per battery charge, a critical competitive advantage.
Integrated Safety and Functional Density: The use of the integrated complementary pair VB5610N allows for the implementation of robust safety features and auxiliary control within a minuscule footprint. This supports essential safety standards while freeing up space and design resources for adding more sensors or computing power.
High Reliability for Demanding Environments: The selected devices feature high voltage ratings, robust packaging, and are suited for industrial temperature ranges. Combined with thoughtful system-level protection and thermal design, this ensures dependable operation amidst vibrations, shocks, and temperature variations encountered in daily delivery tasks.
In the design of power drive systems for smart delivery robots, MOSFET selection is pivotal for achieving efficiency, reliability, safety, and compactness. This scenario-based selection solution, by accurately matching the demands of drive motors, power distribution, and safety circuits, provides a comprehensive, actionable technical guide. As robots evolve towards higher autonomy, longer range, and more complex functionalities, power device selection will increasingly focus on deep integration and intelligence. Future exploration could involve integrating current sensing into MOSFET packages or adopting higher-frequency switching devices to further reduce the size of motor drives and power supplies, laying a solid hardware foundation for the next generation of high-performance, highly reliable smart delivery robots.

Detailed Topology Diagrams