This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Looking for driver for a Single Phase Brushless (BLDC) Motor

Other Parts Discussed in Thread: DRV8701, TMP814, TMP815

Hello all,

I am a design engineer and just starting a new project. I have done some research and it seems that what I am trying to do is quite possible, but probably not the most common. 

I am working on replacing an existing brushed motor / controller with a brushless design with similar specifications. The only tricky part is that the motor has a strange form factor which does not allow motor coils to be placed all the way around the rotor. So the motor will look something like the picture below. I have seen this called a single phase AC motor, and I have also see some call it a single phase brushless motor. I know that these motors can have difficulty starting or being able to change direction. For this project however I do not need the motor to run both directions, just consistently run the same direction. Think of a fan type application.

I am currently working on building the prototype but was looking into controllers. I need to set the speed of the motor and have breaking functionality.  

Motor Specification are:

12v supply power

30-35 amps

1200 -1500 rpm

approximately 2 Nm torque.

I have found this great reference article on TI's site - Drive a Single Phase Brushless DC (BLDC) with a Brushed Motor Driver Reference Design

Seems to show me that this is no a fools errand. I was thinking about getting one of those evaluation boards and giving it a shot. But I thought I would post here and see if anyone might have a suggestion for a better option. 

Any comments or suggestions are appreciated.

Josh

  • Hi Josh,

    The DRV8701 Gate driver would be a good for this application, I would recommend following the reference design suggestion that you posted. This gate driver is best suited for the current level you intend to drive in your motor.

    If you have specific questions on the reference design we can help answer them here.
  • Thank you Phil. I ordered the evaluation board for the DRV8701 and will be working through the reference document. If I have any questions I will let you know. 

    Thanks again,

    Josh

  • Hi Josh,

    A team member of mine recently brought to my attention the TMP814 and TMP815 devices that are intended to be used for applications similar to what you're doing above. The TMP814 has a maximum gate drive current of 50 mA while the DRV8701 has a maximum gate drive current of 150 mA (SINK).

    This may cause slew rate issues in your end application depending on the MOSFETs you select, but the device features of the TMP814 and TMP815 may be better suited to what you're trying to achieve.
  • Phil,

    Thanks for the additional information. I will check out both of those parts as well. Do you carry evaluation boards for the TMP814 or TMP815? I just got the DRV8701 evaluation board and would order the other ones for testing right away.

    Thank you,
    Josh