BOOSTXL-DRV8320RS: 3.3-V, 5-V supply that disturbes with the output during operation

Part Number: BOOSTXL-DRV8320RS
Other Parts Discussed in Thread: LAUNCHXL-F280049C, DRV8320

BOOSTXL-DRV8320RS + LAUNCHXL-F280049C to run the motor drive
Total power supply: 36V lithium battery power supply:

1.The 5-V, 3.3-V power supply on the LAUNCHXL-F280049C is disturbed. The two boards are supplied to the ground together through the wires.

2. The 3.3-V output of the BOOSTXL-DRV8320RS is also disturbed.

The customer would like to know is there any way to remove these disturbances.

Best Regards,
Cherry Zhou

  • Hi Cherry, 

    We are looking into this and will follow up with any additional questions or answers to your e2e post.

    Thanks and Best Regards,

    Andrew 

  • Hi Cherry,

    Also, can you help clarify the items below?: 

    1. For the BOOSTXL-DRV8320RS 3.3V, where is this measurement being taken and what is it being supplied by? 
      1. is it on the J1 header pin#1 for 3.3V?
      2. or is it the output of the DRV8320RS device?
    2. Similar question for the LAUNCHXL-F280049C
      1. for the 5V and 3.3V power supplies, is this coming from the USB, or a BoosterPack, or an external power supply?

    Additional request:

    Thanks and Best Regards,

    Andrew 

  • Hi Andrew,

    For the BOOSTXL-DRV8320RS 3.3V: The measurement is taken in where 3.3 V is present, and as long as the motor is running, the disturbances shown above occur.

    For the LAUNCHXL-F280049C: The source of the disturbances is from the operation of the motor. The 5-V or 3.3-V power supply is good when the motor is not running, either USB or BoosterPack.

    NOTE: These waveforms are all obtained through the oscilloscope.

    Best Regards,

    Cherry

  • Hi Cherry,

    Thanks for the clarification - 

    We are continuing to look into this. In the meantime, please see the points below to see if it helps with the debug:

    - I also added a few questions to see if we can understand the system better & identify problems.

    1. Can you share some additional info about the system's operation?
      1. want to understand more about what frequency the external MOSFETs are switching at, the gate-drive current (IDRIVE setting) and also if there are any ongoing SPI commands occurring that match the frequency of the observed spikes on 5V or 3.3V waveforms.
      2. what is the frequency of the spikes in your waveform screenshot?
    2. do the periodic spikes on the 5.5V and 3.3V waveforms improve if we reduce the values for motor operating voltage, gate drive current, and MOSFET switching frequency?
    3. Can you share some info about how the Launchpad and Boosterpack are wired up to the external FETs and motor?
      1. A capture of the board layout may give some insight into what's causing the problem 
    4. Also, can you send a picture to show how the USB jumpers on the Launchpad are populated? (see image below) 

    Best Regards,

    Andrew 

  • Hi Andrew,

    Frequency the external MOSFETs are switching at 20K.

    The same result should be obtained for routine testing with sensorless foc from F280049C+DRV8320RS (test supply 3.3V, 5V).

    Best Regards,

    Cherry Zhou

  • Hello Cherry,

    Can you please answer the rest of Andrew's questions?

    Thanks,

    Matt

  • Hi Matt,

    Sorry for the late reply.

    1. Frequency the external MOSFETs are switching at 20K. The same result could be obtained for routine testing with sensorless foc from F280049C+DRV8320RS (test supply 3.3V, 5V), please try it.

    2. The LaunchPad and BoosterPack are direct-to-36-V Li-Ion battery power supplies, and ABC three-phase electrodes.

    3. The following figure shows a picture of how USB jumpers on the Launchpad are populated:

    The JP4 3.3V test waveform show disturbances when the motor is running.

    Best Regards,

    Cherry

  • Hi Cherry,

    Thanks for the update - 

    From the picture below, it looks like all three jumpers are populated. Is that correct? 

    - this may be the root cause of the problem, since there are multiple sources for 3.3V that could be shorted together and fighting each other, causing the strange periodic waveform from the DRV8320 device's internal buck regulator.

    In the BOOSTXL-DRV8320RS user guide document, table 3.2 will suggest how to populate these jumpers when docking the boosterpack onto the launchpad. Can you try depopulating the jumpers J1,J2,J3 accordingly to match the table and seeing if those 3.3V/5V waveforms are corrected?

    - link: https://www.ti.com/lit/ug/spruij3b/spruij3b.pdf?ts=1631288042569&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FBOOSTXL-DRV8320RS

    Best Regards,

    Andrew

  • Hi Andrew,

    Thanks for your reply.

    The customer tried to remove the jumper caps from 3.3V-5.5V-GND individually, and then tried to unplug them all. But disturbances are still here. The customer would like to know the reason for that. Thanks a lot.

    Best Regards,

    Cherry

  • Hi Cherry,

    Noted on the latest response - 

    I'll take another look at the user guides for the BoosterPack and LaunchPad this week & see if there are any other suggestions that come to mind. 
    Will keep you updated on progress 

    Best Regards,
    Andrew 

  • Hi Andrew,

    Thank you so much.

    Waiting for the update.

    Best Regards,

    Cherry

  • Hi Cherry,

    I took another look at the user guides below, and have the following feedback:

    First a recap of previous items that have been confirmed as mandatory for the Boosterpack to work:

    1. Jumpers J1, J2, J3 should all be depopulated completely
      1. The boosterpack will provide 3.3V supply to the entire system through the DRV8320RS internal buck regulator. 
    2. Both Jumpers for JP8 should be depopulated, since you are using site1 of the launchpad (the header pins near the top half of board)

    New items to check:

    1. Saw a mention that you are using JP4 for the 3.3V 'test waveform'?
    2. I want to ask: are you supplying 3.3V externally through this connection point (JP4?) Or are you just using that connector to measure 3.3V?
      1. we do not want anything other than the boosterpack's DRV8320 device to be supplying 3.3V - this should come only from the IC 
      2. anything extra in the system supplying 3.3V will fight with the buck regulator output 
      3. Also, if you are using the JP4 as a test point - I am not sure if it is the best connection for your oscilloscope. 
      4. Can you probe the output of the DRV8320 device directly?
        1. this would be near the DRV8320RS device on the boosterpack (highlighted below) 

    Question: what part of your system is supplying the 5V voltage? 

    - is this also being supplied externally through JP5/JP7 or something?

    - Jumpers J1,J2,J3 should still be completely depopulated at this point

    Information on JP4:

    JP4 location on the launchpad:

     

    Best Regards,

    Andrew 

  • Hello Cherry,

    Do you need any additional help on this thread?

    Thanks,

    Matt

  • Hi Cherry, 

    Just wanted to check in on this one and see if the customer's problem has been resolved? 

    From my latest response, we were suggesting a few actions to potentially remove the noise disturbance from the 3.3V rail. 

    • Our main suspicion right now is that there are multiple parts of the board providing 3.3V, which are fighting eachother on the same voltage node 
    • In this DRV8320RS system, the DRV device should be the only one supplying 3.3V in the entire launchpad+boosterpack system.
    • The launchpad will source this 3.3V from the DRV device's integrated buck regulator, and then boost it up to 5V anywhere that 5V is needed. 
      • having a disturbance on 3.3V rail will explain that disturbance being passed forward to the 5V rail

    Thanks and Best Regards,

    Andrew

  • Hi Andrew,

    Sorry for the late reply!

    The customer hasn't offer the info about your question and I am still waiting.

    And I will update your latest respond to the customer to check if it is helpful.

    Thanks again, if there is any updates I will forward to you asap.

    Best Regards,

    Cherry

  • Hello Cherry,

    Sounds good. Please let us know when you have an update.

    Thanks,

    Matt

  • Hi Cherry,

    Just checking in here - please let us know if the customer's problem has been resolved, or if there's additional help needed from us 

    Thanks and Best Regards,
    Andrew

  • Hi Andrew,

    Thanks for your checking, and there is no feedback from the customer and I am still waiting, if there is anything new I will update to you asap.

    Thanks and Best Regards,

    Cherry

  • Hi Cherry, 

    thanks for the update

    Best Regards,

    Andrew 

  • Hi Cherry, 

    Closing this thread for now - please click '+Ask a related question' if you need additional assistance on this item. 

    Thanks and Best Regards,
    Andrew