• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 29 subscribers
  • Views 785 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

DRV8332: Motor driver with minimum no. of inputs?

Puneeth Bandikatla
Intellectual 715 points
Part Number: DRV8332
Other Parts Discussed in Thread: DRV8312, DRV8308, DRV8320, DRV8307

Hi , 

        I want to drive a 3-phase BLDC motor with PRU on  AM437x board with least possible number of GPIOs. BLDC motor's peak current is about 5A and Rated current 3A. I've had a look at DRV 8332 and DRV8312 datasheets and understood that it'll require 3 PWM inputs and 3 RESET inputs(which need to be dynamic in nature i.e these inputs need to change to control the speed of the motor. Correct me if I'm wrong here). Apart from the 3 PWM signals and 3 RESET signals what are the other inputs required which need to be constantly changing in order to control the motor's speed and direction. Is there any way to control a 3-phase BLDC motor with just 3 inputs(can be PWM or high/low toggling)? 

  • 0
    TI__Guru** 114905 points
    Hi Puneeth,

    You are correct in your statement that you need 3 PWM inputs and 3 RESET input for the DRV8312/32.

    Are you planning to drive the motor using trapezoidal or sinusoidal algorithms?
    Does the motor have hall sensors or elements?
    Are you open to using external FETs with a gate driver?

    If so, there are more options available like the DRV8308 and DRV8320 that may be a better fit.
  • 0 in reply to Rick Duncan
    Intellectual 715 points
    Hi Rick,
    I can generate square wave pulses from PRU of my AM437x which is the way I'd ideally want to control it.
    The motor has hall effect sensor(U,V,W) and differential encoder for position control(A+,A-,B+,B-,Z+,Z-).
    If it's possible, I'd like to avoid external circuitry. Please suggest approach with FETs and gate driver as well.
    I see that DRV8308 and DRV8320 use SPI, is this the only way if I have to reduce the no. of GPIOs used?
  • 0 in reply to Puneeth Bandikatla
    TI__Guru** 114905 points
    Hi Puneeth,


    The DRV8307 or DRV8320H could be used to further reduce the number of GPIOs needed. Both of these devices do not have a SPI.
    Both of these devices have a 1X PWM mode. This mode uses the hall sensors to commutate.