SLVAF66 June   2021 DRV3255-Q1 , DRV8300 , DRV8301 , DRV8302 , DRV8303 , DRV8304 , DRV8305 , DRV8305-Q1 , DRV8306 , DRV8307 , DRV8308 , DRV8320 , DRV8320R , DRV8323 , DRV8323R , DRV8340-Q1 , DRV8343-Q1 , DRV8350 , DRV8350F , DRV8350R , DRV8353 , DRV8353F , DRV8353R


  1. Introduction to High-Power Motor Applications
    1. 1.1 Effects of a Poorly-Designed High-Power Motor Driver System
    2. 1.2 Example of the High-Power Design Process
  2. Examining a High-Power Motor Drive System at a High Level
    1. 2.1 Anatomy of the Motor Drive Power Stage and How to Troubleshoot
    2. 2.2 Troubleshooting a High-Power System
  3. High-Power Design Through MOSFETs and MOSFET Gate Current (IDRIVE)
    1. 3.1 MOSFET Gate Current
      1. 3.1.1 How Gate Current Causes Damage
      2. 3.1.2 Gate Resistors and Smart Gate Drive Technology
        1. Gate Resistors
        2. Smart Gate Drive and Internally-Controlled Sink and Source Gate Currents
        3. Summary for Gate Resistors and Smart Gate Drive Technology
      3. 3.1.3 Example Gate Current Calculation for a Given FET
  4. High-Power Design Through External Components
    1. 4.1 Bulk and Decoupling Capacitors
      1. 4.1.1 Note on Capacitor Voltage Ratings
    2. 4.2 RC Snubber Circuits
    3. 4.3 High-Side Drain to Low-Side Source Capacitor
    4. 4.4 Gate-to-GND Diodes
  5. High-Power Design Through a Parallel MOSFET Power Stage
  6. High-Power Design Through Protection
    1. 6.1 VDS and VGS Monitoring
      1. 6.1.1 Turning Off the FETs During an Overcurrent, Shoot-Through, or FET Shorting Event
    2. 6.2 Passive Gate-to-Source Pulldown Resistors
    3. 6.3 Power Supply Reverse Polarity or Power Supply Cutoff Protection
  7. High-Power Design Through Motor Control Methods
    1. 7.1 Brake versus Coast
      1. 7.1.1 Algorithm-Based Solutions
      2. 7.1.2 External Circuit Solutions
      3. 7.1.3 Summary of Brake versus Coast
  8. High-Power Design Through Layout
    1. 8.1 What is a Kelvin Connection?
    2. 8.2 General Layout Advice
  9. Conclusion
  10. 10Acknowledgments

Introduction to High-Power Motor Applications

High power motor applications can range anywhere from lower voltage systems that result in hundreds of watts, such as a 12-V automotive power seats, to multiple kilowatt systems, such as 60-V and 100-A power tools. Typically, these systems use shunt-based current sensing, and non-isolated gate drivers that control large power MOSFETs. While these applications can be powered from a battery or gridded AC power converted to DC, they all have the common goals to be robust and protected against high current and high voltage events that result from shoot-through, short-circuit, overcurrent, MOSFET reverse recovery, or PCB parasitic inductance behavior.

For example, power tools have high power ratings for industrial and household purposes, such as drilling, grinding, cutting, polishing, driving fasteners, and more. Requirements include:

  • Small form factor, as tools are often hand-held
  • High efficiency, as tools are often battery operated
  • High current, as tools must produce high torque to overcome large loads
  • High reliability, as safety is a primary concern if the tool fails
  • Good thermal performance, as high power densities without proper dissipation cause systems to overheat

When designing high power systems, these requirements produce tradeoffs and conflict with each other. In the case of power tools, high current, efficiency, and thermal performance can be an increased with a larger board size which conflicts with the need to be small and hand-held.

This makes high power design very important. Like in the case of Electromagnetic Interference (EMI), designing for high power applications is a process of making decisions and planning to mitigate problems that may or may not occur.