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DRV8305: Can I use DRV8305 with 3.3V supply to drive an Induction motor using TMS320F28069?

Part Number: DRV8305
Other Parts Discussed in Thread: DRV8353, MOTORWARE, CSD19532Q5B, LMG5200, , TMS320F28027F

Hello, 

I am designing a custom board by trying to use the DRV8305 and the F28069 combo, but the DRV8305 has a voltage limit of 60V. My supply voltage will be around 65-70V, so I was thinking of using the DRV8353, but I could not find the files for using DRV8353 in Motorware along with F28069. So I want to know if I can use DRV8305 along with CSD19532Q5B MOSFETs for an ACIM control using InstaSPIN, BUT giving only 5V supply to DRV8305 and 70V supply to the FETs? Is 5V too low for the DRV8305 to operate? I am sorry if I violated the forum rules, just had this doubt that I needed some clarification on. If anyone can answer this, that would be great. 

Thank you,

Ally

  • Hey Ally,

    An expert has been notified to answer any follow up questions you have. Don't worry about violating the forum rules, this is a perfectly reasonable question to ask.

    If I understand your system correctly, you have a supply voltage (65-70V) and would like to use an MCU (F28069 in this case) to take control of the motor drive algorithm (InstaSpin). The MCU interfaces with the gate driver (DRV8305) which then goes to the gates of some FETs (CSD19532Q5B). Is this correct?

    I have a few high level comments. MCU - Gate Driver - FETs is very common and arguably baseline architecture used to drive motor. Some of these components can be integrated in the same chip while some can be split up into different sections (like you're using in this design). Each section has its purpose.

    The MCU takes control of algorithm (when to turn gate of FETs on and off). FETs are the vehicle used to deliver current through the motor phases, which will eventually change into an magnetic field that attracts the rotor. The gate driver can provide protection (AVS, Over temp, etc.), optimize operation (Smart Gate Drive), but, most importantly, translate the signals from the MCU into the voltages necessary to drive the gate of the power MOSFET's. To emphasize this point, if you need 70V on the Drain of you FET's, you'll need 70V + V_threshold (minimum) on the gate to turn on the highside FETs of your half bridge. This means, the gate driver actually produces voltage higher than your supply voltage! This is through charge pumps or boot strap circuits that are usually described in the datasheet.

    So, if the gate driver is has a supply voltage at 5V, its going to have a hard time producing a voltage higher than 70V (usually its some constant voltage above the supply voltage written as VM + 7V or something like that, but there are many different ways to do that). As a result, it sounds like the DRV8305 will not be the part you are looking for, but I will let others comment about what the best part is for you.

    Best,
    -Cole
  • Ally,

    The DRV8353 EVM hardware files are located on TI.com, please search for the EVM webpage and check there.

    You can operate the VM of the DRV8353 with lower voltage such as 9V. The FETs and VDRAIN pin of the DRV can operate up to 100V but this includes any appropriate headroom for when the supply voltage could get lifted by excess motor energy or similar.

    The DRV8353 has a charge pump that is run from the VDRAIN supply so thats why the VM can be lower at 9V.

    For the DRV8305, PVDD must always be the same as the FET voltage and they should be connected to each other.

    Regards,

    -Adam
  • Hello Cole,

    Thank you so much for the information you have provided. This explains a lot! I was never considering the fact that I need more than 70V to turn the high side FET ON. So 8305 is not going to help me.

    Hello Adam,

    Thank you. I am trying to control an Induction motor and in the datasheet for the DRV8353, it says 'highly-integrated gate drivers for three-phase brushless DC (BLDC) motor applications'. So I was confused if I can use it for ACIM control.

    Also, I was going through the benefits of using GaN FETs, and for the power rating I have (70V and -8A to +8A at full load), I came across LMG5200, which fits my application pretty good (rated upto 80V and has integrated gate driver and also smaller footprint). Can I use the LMG5200 with F28069 for the InstaSPIN-FOC control of Induction motor? Will that be a very big learning curve to learn to be able to program the F28069 with LMG5200 for ACIM? I am going through the TIDA00909 reference design and I will try to use it. I don't think I can order the EVM board used in the TIDA00909, so I will be designing it to test it. I am going over the Labs TIDA00909 reference design file, and when I have a board design complete and I have the board with me with LMG5200, I will test it with the launchpad F28069. Hopefully, it works and I don't end up blowing something up, but hey, that's power electronics.

    Thanks a lot once again, I look forward to any comments if anyone has on this.

    -Ally.

  • Ally,

    This forum can help with only the DRV motor drivers, please post in the C2000 forum if you have questions about the C2000 processor.

    Regards,

    -Adam
  • Hey Adam,

    Sorry about that, I did not know there were separate forums. I will post my question on the C2000 forum. But regarding the DRV8353, this can be used for FOC control of ACIM?

    -Ally
  • Ally,

    Unfortunately none of our devices can. They are traditional BLDC motor controllers, not for AC power.

    Regards,

    -Adam
  • Hello Adam,

    That does not make sense, NONE of the devices can be used? This HV kit mentions that it can be used for ACI motors : www.ti.com/.../tmdshvmtrinspin But I cannot find out the gate drivers or the transistors used in the kit.

    So how can you say none of your devices work for AC Power? I am so confused right now.
  • Ally,

    That kit is not developed by the brushless motor drive team, it has no TI gate driver on board. It uses a Mitsubishi power module found here: www.mitsubishielectric-mesh.com/.../ps21765_e.pdf

    Regards,

    -Adam
  • Hello Adam,

    Can you please explain why the DRV8353 cannot be used for ACIM control? I have used the LaunchpadF28069 with the BoostXL-DRV8305EVM board, and just today I was able to get an Induction motor turning, I have done the ACIM identification (Lab2) to get the parameters, and I am going to run Lab5a this week. It is a 220V/1.6A rated, 60Hz, 1400rpm Induction motor. Due to the limit on the booster pack of 45V, I ran the lab with 40V DC input. But for higher voltage, I want to design a powerstage so I can run the motor with higher voltages. The final induction motor for which I am designing the controller for, will be running at desired speed at 70V drawing around 8A. I do not have the final motor with me yet, so I am doing this so as to get to a motor controller for ACIM.

    -Ally
  • Ally,

    I apologize, I was confused. I clarified with my colleague and actually the DRV8353 can be used for ACIM control. The issue is that the Instaspin code (written by the C2000 team) only runs on the TMS320F28027F processor, F28069 is not compatible.

    Regards,

    -Adam
  • Hello Adam,

    Just to clarify, I cannot use LaunchPad-F28069 with DRV8353? I have gotten the software files for DRV8353RH, and I found the following:

    So I downloaded the zip file from TI, and extracted the folder into my Motorware directory, and now, I can see that there is a Hal folder with F2806x in the DRV8353 directory. Because even the F28069 launchPad is Insta-Spin enabled, so I want to confirm if I cannot work DRV8353 board with F28069? I will work with F28027F launchPad if this does not work. The reason I am choosing F28069 is the ability to control 2 motors with 1 MCU, which 28027F does not have. So that later on, If I decide to develop a further iteration of my design to control 2 motors, I will not have to move to a different MCU. Also, I will have to order a new F28027 launchpad as well, which I wanted to avoid if the F28069 will do the work. 

    -Ally.

  • Ally,

    You should ask the C2000 team these questions, they developed the Instaspin code and support it as well as this is their processor.

    Regards,

    -Adam
  • Adam,

    I saw on some posts that some TI employees would transfer the post to a different forum if the solution would be found there. So is there a way to link this to my post there, or I should I just post a new query? and give a URL link to this?

    - Ally
  • Ally,

    It would be best to make a new post in the C2000 forum as to not cloudy the issue. You can link there to this post if needed.

    Regards,

    -Adam
  • Adam,

    Okay, I will do a little bit more research and try to find out more about the F28069 and DRV8353. I will post a separate question on the C2000 forum on what I get. I will also run the Labs 2,3,4 and 5 on the LaunchPad-F28069 and DRV8305 combo.
    Thank you so much once again for helping me out and giving quick replies. And also, by just going through a few of the questions other people had with the DRV8305 and DRV8353 gave me good information. There's so much to learn!

    Thank you,
    Ally