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Diodes Incorporated


Diodes Incorporated Brushed and Brushless DC Motors

Brushed DC motors are composed of a rotor with electromagnets and a stator with permanent magnets. The graphics below illustrate the construction and operation of a simple two-pole brushed DC motor works.

  • The rotational speed of a DC motor is proportional to the back EMF across its coils.
  • Torque is proportional to current.
  • When the voltage remains constant an increase in load (torque) on the motor results in a decrease in speed.
  • The relationship between speed and torque is shown in a motors speed - torque (below). Torque and speed are said to be inversely proportional.

Super Barrier Rectifier (SBR®) combines both a lower forward loss compared to a Schottky Barrier diode (SBD) with thermal stability of a Fast Recovery diode (FRD)

These advantages over existing technologies translate to…

  • Higher Efficiency and Higher Temperature Operation
    • SBR® enables lower VF with more stable reverse leakage current allowing applications to run more efficiently at higher ambient temperature, resulting in more power savings and higher reliability
  • Better Performance in Smaller Packages
    • SBR® patented high density cellular technology enables SBR® to exceed customers’ ever increasing demand for high performance in smaller packages
  • Scalable technology
    • Lack of metal Schottky barrier and use of CMOS process allows for a scalable technology from 0.1A to 60A and 20V to 400V without degradation of performance

Device Structure and Operation of SBR®

  • SBR® is Patented and Proprietary Technology of Diodes Inc.
  • Traditional (two terminal) device by shorting the gate and source together (shown in red)
  • In forward mode, device operates as majority carrier (MOS) with low VF and fast switching
  • In reverse mode, electrostatic behaviour causes depletion mode, substantially reducing leakage current
  • Cellular design operates as thousands of individual devices working in parallel
Diodes Incorporated – Device Structure and Operation of SBR

Brushless DC Motors (BLDC)

  • Improved battery performance suited for hand held power tools
  • Government standards requiring more efficient energy usage
  • 60 to 70% of industrial electricity usage is in motor drive
  • All BLDC motors require electronic control to drive the motor
  • Diodes Inc. offers Gate Drivers, MOSFETs, Hall Sensors, discretes

3-Phase BLDC Motor Driving Example

Diodes Incorporated – 3-Phase BLDC Motor Driving Example

DMT Shielded Gate Technology

This MOSFET is designed to meet the stringent requirements of Automotive applications. It is qualified to AEC-Q101, supported by a PPAP.


  • Rated to +175°C – Ideal for High Ambient Temperature Environments
  • Thermally Efficient Package for Cooler Running Applications
  • High Conversion Efficiency
  • Low RDS(ON) – Minimises On-State Losses
  • Low Input Capacitance
  • Fast Switching Speed
  • <1.1mm Package Profile – Ideal for Thin Applications
Diodes Incorporated – DMT Shielded Gate Technology