In the era of smart manufacturing and flexible production, AI dual-arm composite cooperative robots, as core execution units, see their performance—encompassing precision, speed, dexterity, and safety—directly determined by the capabilities of their joint servo drive and onboard power management systems. The servo drivers, compact DC-DC converters, and intelligent safety power distribution units act as the robot's "muscles, heart, and nervous system," responsible for delivering high dynamic, high torque density motion control and ensuring reliable, safe operation within collaborative workspaces. The selection of power semiconductors profoundly impacts system power density, dynamic response efficiency, thermal management in confined spaces, and functional safety. This article, targeting the demanding application scenario of advanced collaborative robots—characterized by stringent requirements for compactness, efficiency, dynamic response, and safety compliance (e.g., SIL/PL)—conducts an in-depth analysis of device selection considerations for key power nodes, providing a complete and optimized recommendation scheme.
Detailed Device Selection Analysis
1. VBGQT1801 (N-MOS, 80V, 350A, TOLL)
Role: Main switch in high-current, low-voltage motor drive phase legs (inverter stage) for joint servos.
Technical Deep Dive:
Ultimate Efficiency for Peak Torque: Robotic joints require high peak current for instantaneous torque. The 80V rating provides ample margin for common 48V or lower servo bus voltages. Utilizing SGT (Shielded Gate Trench) technology, its Rds(on) is as low as 1mΩ at 10V drive, combined with a massive 350A continuous current capability, minimizing conduction losses during high-torque maneuvers, which is critical for efficiency and thermal management in a sealed joint module.
Power Density & Thermal Performance: The TOLL (TO-Leadless) package offers an excellent footprint-to-performance ratio and superior thermal resistance from top and bottom, making it ideal for direct mounting onto compact liquid-cooled or heatsink surfaces within the densely packed robot arm structure. Its low-loss characteristics directly reduce heat generation, easing thermal design challenges.
Dynamic Response: Extremely low gate charge and output capacitance enable high PWM switching frequencies (tens to hundreds of kHz), crucial for achieving high bandwidth current control, reducing torque ripple, and enabling smooth, precise motion—a key requirement for delicate assembly or human collaboration tasks.
2. VBMB165R26S (N-MOS, 650V, 26A, TO220F)
Role: Main switch in the central onboard AC-DC or isolated DC-DC power supply unit, or as a bus switch for safety isolation.
Extended Application Analysis:
Robust Power Conversion Core: For robots powered from a higher voltage industrial bus (e.g., 400VAC) or requiring an intermediate high-voltage DC bus, the 650V rating provides a reliable safety margin. Its Super Junction Multi-EPI technology balances good switching performance with a low Rds(on) of 115mΩ, ensuring efficient power conversion in the main supply module.
Compactness & Reliability: The TO220F (fully insulated) package allows for easy mounting without an isolation pad, simplifying assembly and improving heat transfer to the chassis or a shared heatsink in the robot base. This is ideal for creating a compact, high-reliability power "backend" that converts and distributes power to various arm sections.
Safety Function Potential: Its voltage rating and package make it suitable for use as a robust, fast-acting solid-state disconnect switch on the main DC bus, enabling rapid power cutoff for safety functions when integrated with appropriate monitoring circuits.
3. VBA1101M (N-MOS, 100V, 4.2A, SOP8)
Role: Intelligent power distribution, safety circuit control, and low-power subsystem switching (e.g., sensor array power, brake control, LED/indicator, communication module power).
Precision Power & Safety Management:
High-Integration Intelligent Control: This MOSFET in a compact SOP8 package offers a 100V rating suitable for 24V or 48V auxiliary rails within the robot. Its low on-resistance (~124mΩ @10V) ensures minimal voltage drop when powering critical sensors or safety devices.
Enabler for Functional Safety: The device can be used as a high-side or low-side switch to independently control power to safety-critical loads like joint brakes, safety-rated sensor circuits, or redundant monitoring modules. This allows for the implementation of hardware-based safety loops, enabling immediate de-energization of specific functions upon a fault detection, which is fundamental for achieving high Safety Integrity Levels (SIL) or Performance Levels (PL).
Space-Saving & Reliability: The small footprint allows dense placement on control PCBs, enabling modular and distributed power management across the robot's body and arms. Trench technology provides stable performance over the robot's operational life, enduring vibrations and thermal cycles.
System-Level Design and Application Recommendations
Drive Circuit Design Key Points:
High-Current Motor Drive (VBGQT1801): Requires a high-current gate driver with proper shoot-through protection. Careful PCB layout with minimized power loop inductance is paramount to suppress voltage spikes and ensure clean switching, which directly affects EMI and reliability.
Main Supply Switch (VBMB165R26S): Needs a standard gate driver. Attention should be paid to managing switching node dv/dt to reduce noise coupling into sensitive control circuits. Use of an RC snubber may be beneficial.
Intelligent/Safety Switch (VBA1101M): Can be driven directly by an MCU GPIO via a simple buffer. For safety-critical paths, redundant driving or monitoring circuits are recommended. Incorporate TVS and filtering at the gate for robustness.
Thermal Management and EMC Design:
Tiered Thermal Design: VBGQT1801 demands direct thermal interface with joint housing or a dedicated cooler. VBMB165R26S in the base can use chassis or a forced-air heatsink. VBA1101M dissipates heat primarily through PCB copper pours.
EMI Suppression: Employ careful partitioning between high dv/dt motor drive circuits (using VBGQT1801) and sensitive analog/sensor areas. Use shielded cables for motor connections. Place decoupling capacitors close to all devices. The compact nature of robots makes proper grounding and shielding strategies critical.
Reliability & Safety Enhancement Measures:
Adequate Derating: Operate all devices well within their voltage and current ratings, considering regenerative energy from motor braking. Strictly monitor junction temperature, especially for VBGQT1801 in the sealed arm environment.
Dual-Channel Safety: For functions controlled by devices like VBA1101M that are part of safety chains, implement dual-channel monitoring with cross-checking in the controller to meet relevant safety standards.
Enhanced Protection: Integrate comprehensive overcurrent, overtemperature, and undervoltage lockout (UVLO) protection at both the drive and system levels. Use TVS diodes on all external connections and power rails susceptible to transients.
Conclusion
In the design of high-performance, safe, and compact power systems for AI dual-arm composite cooperative robots, power semiconductor selection is key to achieving dynamic motion, intelligent power management, and collaborative safety. The three-tier device scheme recommended in this article embodies the design philosophy of high dynamic response, high integration, and intrinsic safety.
Core value is reflected in:
High Torque Density & Dynamic Fidelity: The VBGQT1801 enables efficient, high-current switching essential for powerful and responsive joint control, forming the foundation for precise and dexterous movement.
Compact & Reliable Power Backbone: The VBMB165R26S provides a robust and efficient solution for the central power conversion, ensuring stable energy delivery to all subsystems within a minimal footprint.
Intelligent Safety & Modularity: The VBA1101M facilitates distributed, intelligent power control, enabling hardware-enforced safety functions and modular power management for sensors and peripherals, which is critical for functional safety certification and flexible robot configuration.
Future Trends:
As collaborative robots evolve towards higher power density, more integrated sensing, and advanced safety features, power device selection will trend towards:
Increased adoption of highly integrated IPMs (Intelligent Power Modules) or motor driver SoCs that combine control, drive, and protection for further size reduction.
Use of GaN FETs in intermediate bus converters or high-frequency motor drives to push switching frequencies even higher, reducing filter component size and enabling new control techniques.
Smart Power Switches with integrated current sensing, diagnostic feedback, and digital interfaces (e.g., SPI) for enhanced health monitoring and predictive maintenance.
This recommended scheme provides a complete power device solution for AI dual-arm robots, spanning from central power conversion to joint-level drive and down to intelligent safety distribution. Engineers can refine it based on specific joint power ratings, bus voltage architecture (e.g., 48V vs. higher voltage), and targeted safety compliance levels to build robust, high-performance robotic systems that are the cornerstone of advanced, safe, and flexible automation.

Detailed Topology Diagrams