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DRV8353RS-EVM: Get GDF Fault When I click on "Start Motor" button from GUI in my my new EVM

Anil Sudhakaran
Expert 1125 points
Part Number: DRV8353RS-EVM
Other Parts Discussed in Thread: DRV8353

Hi ,

Just powered up my new  EVM today. 

Driver board shows Green 3.3V LED,  and Orange LED.  Communicates with GUI.

In GUI, when "System Enable" is enabled  and clicked on "Start Motor" , Fault LED glows.  Motor shaft does not move.

It goes to Motor indentification in first run, after some time green led comes on in Motor identification. Next "start motor" also, red  fault led continue to glow.

Motor takes current around 80 mA. DC voltage is 25V. No extra current when Start motor is pressed.

I probed, PWM signals from micro controller. They all are toggling. DRV chip output side, top side PWM signals are all 1. Low side  PWM signals are all 0.

Please help to identify the issue and make the motor run.

I am attaching the error Register screen shot. GDF bit is set as 1.

Regards,

Anil

  • 0
    TI__Genius 13550 points

    Hi Anil,

    Thank you for posting to the Motor Drivers forum!

    After the fault occurs, can you hit the "Read all registers" button, because if there is a GDF reported in the Fault Status 1 register, then there should be a fault bit set in the VGS Status 2 register to indicate which MOSFET caused the VGS fault?

    Also, what gate drive strength are you using when switching the MOSFETs? It could be that your IDRIVE setting is too high. I would recommend using the lowest IDRIVE setting allowed for the device as the MOSFETs on the EVM are low Qgd, and it doesn't take much gate current to switch the MOSFETs quickly.

    Best,

    ~Alicia

  • 0 in reply to Alicia Rosenberger
    Expert 1125 points

    Hi Alicia,

    Please find below  2 images - details of all the 8 registers before and  after the fault occurs. Pls suggest what  to do next.

    Regards,

    Anil

  • 0 in reply to Anil Sudhakaran
    TI__Genius 13550 points

    Hi Anil,

    I would recommend checking to see if a short between the MOSFET's G terminal and the MOSFET's S terminal. What could have happened was that the IDRIVE setting was too high which caused ringing on the gate/source which could have violated the absolute max of the pins of the device. 

    Best,

    ~Alicia

  • 0 in reply to Alicia Rosenberger
    Expert 1125 points

    Hi Alicia,

    Q4 , Gate to Source is showing short.

    Q6 , gate to source is showing  open (with multimeter) when checked with both probe combinations 

    Other Mosfets shows open with one probe combination and 500-1300 mV with other probe combination.

    Shoul I replace both Q4 and Q6 ?

    I am using default .out program available with new board / GUI.   How IDRIVE will get changed ?

    Regards,

    Anil

  • 0 in reply to Anil Sudhakaran
    TI__Genius 13550 points

    Hi Anil,

    Because you are using the SPI version of the device with the GUI, you can change IDRIVE with the GUI by writing to the Gate Drive HS and Gate Drive LS registers. Refer to section 8.6.2.2 Gate Drive HS Register and section 8.6.2.3 Gate Drive LS Register to see which bit values correspond to which IDRIVE settings.

    Just to make sure that it's the MOSFETs that are causing the issue, I would recommend removing those MOSFETs and checking for a short on the G and S Pads just to make sure that the issue is not with the driver or PCB itself.

    Best,

    ~Alicia

  • 0 in reply to Alicia Rosenberger
    Expert 1125 points

    Hi Alicia,

    Removed  Mosfet Q4.   It still shows short between G and S.  (Across C8 ). Remove driver IC next or is there anything else I can check before removing driver IC?

    In GUI, could not find any option to change IDRIVE setting.  Could you please crosscheck this ? As per one  of the post , 

    • Hao,
    • This is intentional. The IDRIVE has been selected to match the parameters of the FETs which are installed on the EVM. The IDRIVE is locked for the EVM GUI and EVM hardware.
    • Regards,
    • -Adam

    https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/810907/drv8353rs-evm-unable-to-adjust-idrive

    I am suspecting I received a faulty board !!!!

    Regards,

    Anil

  • 0 in reply to Anil Sudhakaran
    TI__Genius 13550 points

    Hi Anil,

    I will check with the team internally to see if there is a way to change the IDRIVVE with the GUI. In the meantime, I would recommend removing the driver and seeing it the short between G and S still exists. 

    Best,

    ~Alicia

  • 0 in reply to Alicia Rosenberger
    Expert 1125 points

    Hi Alicia,

    I have ordered DRV8353 chip. Will take a few days to receive it.  Will be able to remove DRV IC and look for short only after receiving the new IC.

    Looking at so many  discussions in the forum on GDF fault with MOSFET and DRV8353 failures  seen by so many people , I feel there is basic design issue with   the EVM board, DRV chip or firmware.   Please discuss  with your team and come back with fail proof solution to avoid these failures  again.

    I am concerned ,  after replacing the ICs, again there can be similar failures.  See below a few similar issues disucssion...

    e2e.ti.com/.../drv8353rs-evm-gate-drive-fault-gdf

    https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1170147/drv8353rs-evm-gdf-error-troubleshooting

    Regards,

    Anil

  • 0 in reply to Anil Sudhakaran
    TI__Genius 13550 points

    Hi Anil,

    Thank you for the feedback, I will reach out to the team internally and will let you know what I find out.

    Best,

    ~Alicia

  • 0 in reply to Anil Sudhakaran
    TI__Genius 13550 points

    Hi Anil,

    The MOSFETs used on the DRV8353Rx-EVM is very low Qgd, so it doesn't take much gate current to switch the MOSFETs quickly. Because of this, it is not uncommon for the DRV8353Rx-EVMs to get burnt out due an IDRIVE setting that is too large, which is why it is recommended to use the lowest setting.

    Anil Sudhakaran said:
    In GUI, could not find any option to change IDRIVE setting.  Could you please crosscheck this ? As per one  of the post , 

    The IDRIVE setting can be changed in the follow registers (Gate drive HS & Gate Drive LS) by doing the following:

    1. Select Gate drive HS to open Field View
    2. Open drop-down menu for IDRIVEP_HS/IDRIVEN_HS and select the lowest setting, as shown below
    3. Once the lowest setting have been chosen for both IDRIVEP_HS and IDRIVEN_HS press the "WRITE REGISTER" button which should be enabled (located to the right of the "READ ALL REGISTERS" button
    4. Repeat with Gate Drive LS for IDRIVEP_LS and IDRIVEN_LS

    Best,

    ~Alicia

  • 0 in reply to Alicia Rosenberger
    TI__Genius 13550 points

    Hi Anil,

    Please click the resolve button to let us know if this issue has been resolved. I am going to close for now, if you have any additional questions, please feel free to reopen this thread.

    Best,

    ~Alicia