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DRV10975: No current on motor leads

Alex Sanderson
Prodigy 30 points
Part Number: DRV10975
Other Parts Discussed in Thread: USB2ANY, DRV8316, DRV8304, DRV8313, DRV8323R, , MCF8329A, DRV8334, DRV8329

Tool/software:

Hello,

I am attempting to use DRV10975 to control a small 3 phase 6V brushless motor out of a drone. I currently am not using a MCU to control anything, just a PWM input to the SPEED pin created from a 555 timer outputting 75 kHZ and a 4V signal to the DIR pin to enable it. I also tried to hook up a FG to drive the PWM input to the SPEED pin and there was no change. There is slight twitching from the motor and according to the differential scope it is trying to go into a start up mode. When I wired in a current shunt to motor phase U, a minimal current output occurred roughly 0.1uA which would not be enough current to fight the inertia of any BLDC motor. Can anyone point me in a direction of guidance here as to why I have limited current on my phase leads? Could it possible that because I have SCL and SDA floating due to no MCU that there is a power dissipation not allowing my motor to get enough current? 

Thanks,

Alex

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  • 0
    TI__Expert 6011 points

    Hi Alex,

    Do you have an USB2ANY to communicate to the EVM?

    Regards,

    Sachin S

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    I am attempting to do this project with no software or programming. Not sure if this helps but I also just realized that there is no voltage output from U V W pins. Looking at the datasheet it seems as the output should match the VCC input. 

    Thanks,

    Alex 

  • 0 in reply to Alex Sanderson
    TI__Expert 6011 points

    Hi Alex,

    The device actually needs some level of tuning before you can start spinning a motor. I suggest you to connect the device through an USB to the GUI and program it. Once programmed, the device can run without any software since the configuration can be stored in an EEPROM.

    Regards,
    Sachin S

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    I currently am not using any sort of EVM either. All that I have is a DRV10975 soldered to a dip adapter that is placed into a breadboard. Is there a way to still use this USB2ANY? Or is there an alternative DRV controller that I can use that will not require me to "tune" it upon arrival? I could not find a schematic of the EVM board for the DRV10975 or else I would try and lay it out myself and use the USB2ANY. Let me know what you think I should do.

    Also on hand I have DRV8316, DRV8323R, DRV8313, and DRV8304 will any of these be a better option? 

    Thanks,

    Alex

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    I came across another forum earlier today that stated I did not need to use the USB2ANY or another type of I2C communication if I am able to just provide a PWM signal. Why is it that I have to "tune" the IC before I can drive my motor. I was under the impression that the IC should come loaded with the proper register bit settings to at least run the motor even if it is not quite as efficient as it could be. 

    Thanks,

    Alex 

  • 0 in reply to Alex Sanderson
    TI__Expert 6011 points

    Hi Alex,

    The DRV10975 uses motor parameters to drive the motor. I feel we may not be able to spin the motor without tuning the parameters, it maybe trying to run with default values and hitting a fault condition

    Regards,

    Sachin S

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    So I was right to make the assumption that the DRV10975 comes somewhat preprogrammed but may not specifically run every motor hooked to it until it is "tuned". Back to the other question then, once I get the USB2ANY in the mail that I just ordered can I use breadboard jumper wires and jumper the J-Tag cable to my breadboard with the DRV10975 on it? Assuming that I can find a pinout for USB2ANY and the evaluation board I should just be able to wire it up as if it were like the eval circuit. Let me know if this makes sense.

    Thanks,

    Alex 

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    Reading through the data sheet for the USB2ANY and DRV10975EVM it seems as if the only 3 pins that I need from the J4 port of the USB2ANY are SCL, SDA, and GND. Considering that I can supply my own PWM input I think that this would be the case. I also have restructured my circuit to match the circuit that I have provided below this message. Let me know if you can think of anything else.

    Thanks,

    Alex 

  • 0 in reply to Alex Sanderson
    TI__Expert 6011 points

    Hi Alex,

    Alex Sanderson said:
    Back to the other question then, once I get the USB2ANY in the mail that I just ordered can I use breadboard jumper wires and jumper the J-Tag cable to my breadboard with the DRV10975 on it? Assuming that I can find a pinout for USB2ANY and the evaluation board I should just be able to wire it up as if it were like the eval circuit

    Yes this is correct.

    To you second question,

    Please also make sure you have pull up resistors on SCL and SDA:

    Regards,

    Sachin S

  • 0 in reply to Sachin S
    Prodigy 30 points
    Just following up with again. I was able to get the motor running using the DRV10975 GUI, but I want to try and find another product now that I have this project properly rotating. I need a similar IC that will be a higher voltage threshold 8-48V range if at all possible. As for a no-load current roughly 2-3A should be enough but I need to have external MOSFETs so I cannot have them integrated into the IC already. Is there a ASIC that you can think of that TI sells that would fit these qualifications. 
    Thanks,
    Alex 
  • 0 in reply to Alex Sanderson
    TI__Expert 6011 points

    Hi Alex,

    Great to hear you are able to spin the motor. 

    You could look at the MCF8329A - it has an integrated FOC controller and is a gate driver supporting upto 60V.

    Regards,

    Sachin S

  • 0 in reply to Sachin S
    Prodigy 30 points

    Hi Sachin,

    Will that drive be the most similar to DRV10975 beside the integrated FETs? I was looking at possible alternatives of DRV8329 and DRV8334 as well. Let me know what you think of either of these choices.

    Thanks,

    Alex

  • 0 in reply to Alex Sanderson
    TI__Expert 6011 points

    Hi Alex,

    Could you raise another e2e thread for this? This helps other members of the e2e community to track answers easily. 

    I am in the team which works on the integrated controllers (MCx, DRV10x) products. DRV8x products are handled by a sister-team within our team. Please mention the part names DRV8329 and DRV8334 so that the respective person will respond. 

    But I am sure we have products similar to your request.

    Regards,
    Sachin S