With the expansion of flexible manufacturing and human-robot collaboration, high-end collaborative robots have become core assets in the leasing service market. Their motion control, power distribution, and safety systems directly determine operational precision, energy efficiency, lease cost, and long-term service reliability. As the core switching components in motor drives and power management circuits, the selection of power devices (MOSFETs/IGBTs) profoundly impacts system efficiency, power density, thermal performance, and lifespan. Addressing the requirements for high dynamic response, compact integration, and 24/7 operational reliability in collaborative robots, this guide proposes a systematic power device selection and implementation solution with a scenario-driven design philosophy.
I. Overall Selection Principles: Performance Density and Reliability Balance
Device selection must balance electrical performance, thermal characteristics, package size, and long-term reliability, moving beyond singular parameter optimization to achieve optimal system-level synergy.
Voltage/Current Margin: Based on common DC bus voltages (24V, 48V, or higher), select devices with a voltage rating margin ≥50% to handle regenerative braking voltage spikes. Current rating should support continuous and peak torque demands, with derating to 60-70% of rated current for continuous operation.
Low Loss Priority: Prioritize low on-resistance (Rds(on)) to minimize conduction loss in motor drives. For switching frequency-sensitive applications, consider devices with low gate charge (Qg) and output capacitance (Coss) to reduce dynamic losses and enable higher PWM frequencies for quieter operation.
Package and Thermal Coordination: Choose packages that offer low thermal resistance and suit power density goals (e.g., TO-247, TO-220 for high power; SMD for compact control boards). Design PCB layouts with adequate copper area and thermal vias for effective heat dissipation.
Ruggedness and Lifespan: For leasing models requiring robust operation across diverse environments, focus on devices with high ESD tolerance, avalanche energy rating, and stable parameters over temperature and time.
II. Scenario-Specific Device Selection Strategies
The core electrical loads in a collaborative robot include joint motor drives, auxiliary sensor/controller power rails, and multi-channel power distribution. Each requires tailored device characteristics.
Scenario 1: High-Current Joint Motor Drive (48V Bus, Peak >100A)
Joint actuators demand high efficiency, excellent thermal performance, and high peak current capability for dynamic motion and torque control.
Recommended Model: VBGE1805 (N-MOS, 80V, 120A, TO-252)
Parameter Advantages:
Utilizes advanced SGT technology, achieving an ultra-low Rds(on) of 4.6 mΩ (@10V), drastically reducing conduction losses.
High continuous current (120A) and high peak capability, suitable for servo drive inverters requiring high torque density.
TO-252 package offers a good balance of power handling and footprint, facilitating efficient PCB thermal design.
Scenario Value:
Enables high-efficiency motor drives (>97%), reducing energy consumption and heat generation, critical for leased asset operational cost.
Supports high switching frequencies for precise current control, contributing to smooth, low-noise robot motion.
Design Notes:
Requires a dedicated high-current gate driver IC with adequate sink/source capability.
Implement meticulous PCB layout with a large power plane and thermal vias under the package.
Scenario 2: Sensor & Communication Module Power Management (12V/24V Rails, <10W)
These low-power but always-on or frequently switched circuits require high integration, low gate drive voltage, and minimal standby loss.
Recommended Model: VBI1101M (N-MOS, 100V, 4.2A, SOT89)
Parameter Advantages:
Low Rds(on) of 102 mΩ (@10V) ensures minimal voltage drop in power path switches.
Low gate threshold voltage (Vth ~1.8V) allows direct drive from 3.3V/5V microcontrollers, simplifying design.
Compact SOT89 package saves board space while providing decent thermal performance via PCB copper.
Scenario Value:
Ideal for host-controlled power switching of vision sensors, LiDAR, or wireless modules, enabling deep sleep modes and reducing overall system standby power.
Can be used in point-of-load DC-DC converter synchronous rectification stages.
Design Notes:
Include a small gate series resistor (e.g., 10-47Ω) to damp ringing.
Ensure proper trace width for the load current to minimize conduction loss.
Scenario 3: Multi-Channel Load Switching & Power Distribution
For distributed control of end-effectors, lights, or safety circuits, integrated multi-channel switches save space and simplify control logic.
Recommended Model: VBA3638 (Dual N-MOS, 60V, 7A per channel, SOP8)
Parameter Advantages:
Integrates two low-Rds(on) (28 mΩ @10V) N-channel MOSFETs in one package.
Low Vth (1.7V) compatible with logic-level control.
SOP8 package offers significant space savings compared to two discrete MOSFETs.
Scenario Value:
Enables compact, centralized control of multiple auxiliary loads or safety-rated output channels.
Independent channel control facilitates intelligent power sequencing and fault isolation.
Design Notes:
Can be configured for high-side or low-side switching based on system architecture.
For high-side use, employ a simple charge pump or dedicated high-side driver.
III. Key Implementation Points for System Design
Drive Circuit Optimization:
For VBGE1805, use a robust gate driver (≥2A peak) with proper turn-on/off speed control to balance loss and EMI.
For logic-level MOSFETs (VBI1101M, VBA3638), ensure MCU GPIO can provide sufficient gate current; series resistors are recommended.
Thermal Management Design:
Employ a tiered strategy: VBGE1805 on a dedicated power board with possible heatsink attachment; VBI1101M and VBA3638 rely on PCB copper pours.
Monitor junction temperature via estimators or sensors, especially for joint drives under continuous high-torque operation.
EMC and Reliability Enhancement:
Use RC snubbers or small TVS diodes across MOSFET drains and sources in motor drives to clamp voltage spikes from cable inductance.
Implement comprehensive protection: overcurrent detection, desaturation detection for IGBTs/MOSFETs in drives, and TVS diodes on all external interfaces.
IV. Solution Value and Expansion Recommendations
Core Value:
High Performance & Efficiency: The combination of ultra-low Rds(on) VBGE1805 and efficient switching minimizes energy waste, extending operational time per charge for battery-backed units and reducing electricity costs.
Enhanced Integration & Reliability: The use of integrated multi-channel switches (VBA3638) and logic-level devices (VBI1101M) reduces component count, increases reliability, and supports more compact control electronics.
Leasing-Service Optimized: The focus on ruggedness, thermal performance, and long-term parameter stability aligns with the need for low maintenance and high uptime in rental fleets.
Optimization Recommendations:
Higher Power: For robots with >1kW joint motors, consider higher voltage/current devices in TO-247 packages or parallel configurations of VBGE1805.
Advanced Integration: For ultimate space savings, explore multi-channel driver ICs with integrated MOSFETs (Intelligent Power Stages).
Functional Safety: For safety-critical power isolation, incorporate high-side switches with diagnostic feedback (e.g., PROFET™ style devices) in addition to basic MOSFETs.
Regenerative Braking: For efficient brake energy management, design the DC bus capacitor bank and braking circuit using high-voltage MOSFETs like VBE17R07S if the bus exceeds 48V.
Conclusion
Strategic selection of power semiconductors is fundamental to achieving the high efficiency, compact design, and unwavering reliability demanded by high-end collaborative robots in leasing service models. The scenario-based approach outlined here provides a roadmap for optimizing motor drive and power management subsystems. As robot capabilities evolve, future designs may incorporate wide-bandgap devices (SiC/GaN) for even higher efficiency and power density, further enhancing the value proposition of robot leasing services.

Detailed Topology Diagrams