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DRV10975EVM - Motor does not spin normally

Guru 19775 points
Other Parts Discussed in Thread: DRV10975, DRV10975EVM, DRV10983

Hello Team,

Could you please help us evaluating DRV10975 ? Our customer started evaluating the device with the EVM. When they applied power VCC=12 with motor connected, motor only span once a second. They had set JP2 to ANALOG-SP (Pin1-2), and POT to the maximum setting (around 3.3V).

Do you have any idea what is wrong with the procedure ? I believe DRV10975EVM could simply spin motor without using the GUI.

I have seen similar post in the following link. I have asked customer to try raising the VCC voltage up to 18V.

e2e.ti.com/.../422349

Best Regards,

Kawai

  • Hi Kawai-san,

    Our experts have been contacted and should reply soon.

    Is this a customer supplied motor? If so, what are the motor specifications?
  • Hello Rick-san,

    Yes, customer is using their motor. Below are the specification.
    Please help us supporting our customer. We would like to advise them by today, 11/24 Tuesday Japan time.
    Any advice would be greatly appreciated.

    - Supply Voltage : 12V +/-5%
    - Type : 12 poles, 3 phase brush less, sensor less DC motor
    - Speed of rotation : 10800 [min^-1]
    - Direction of rotation : CW
    - No load current : 250mA MAX
    - KT : 0.0062 [Nm/A] +/-10%
    - Terminal resistance : 1.82 Ohm +/-15%
    - Inductance : 1.0mH MAX

    Best Regards,
    Kawai

  • Kawai- san

    Yes, motor should spin without GUI.

    Before that,  has customer already tuned the parameters ? and the parameters are updated in internal EEPROM?

    If it's not done there is a possibility that default parameters try to spin the motor but fail to do so since motor  is different.

    Please follow the tuning procedure  in that case

    Jasraj

  • Hello Jasraj-san,

    From the motor datasheet, some parameter has different unit such like KT. Customer motor specification has [Nm/A] however DRV10975 Tuning Guide has [mV/Hz]. Also, some of the parameters are not shown in the datasheet. What are the key parameter required to be programmed to the EEPROM for the device to at least spin this motor in normal speed ?

    TI Japan local FAE will send you the motor datasheet. Could you please advise us the recommended parameters which should be programmed to the EEPROM using this motor ?

    Best Regards,
    Kawai
  • Kawai-san,

    Please have a look at the tunig guide document. http://www.ti.com/lit/ug/slou395c/slou395c.pdf. It contains step by step procedure to tune any motor for DRV10975 and DRV10983

    If the motor is available with you, few measurements as per the guide will get us all the relevant parameters to be put in GUI.

     

    Thanks,

    Jasraj

  • Hello Jasraj-san,

    I understand the DRV10975 needs the parameters to be optimized based on the motors. Is the default parameter optimized for the EVM motor (Runtian motor) ? I've asked customer to try spinning the EVM motor. However, the motor speed is still slow and stops even if the POT is set to the maximum (Turned the POT clock wise).

    They had loaded the Runtian motor .csv file. After loading the parameter information, do you need to write to the EEPROM ?
    If so, I believe user should write "B6" to the EEPROM Key and click "eeWrite". Would you also need a new power cycle for the device after writing EEPROM ?

    If I had the EVM kit, I could evaluate the device myself but unfortunately I do not have one at my hand. I am also asking if they could send us the EVM and their motors, so we could optimize the settings.
    Your continuous support would be greatly appreciated.

    Best Regards,
    Kawai
  • Kawai-san,

    During eeprom programming power supply needs to be more than 22V.

    After eeWrite,eerefresh also needs to be done. After Power recycle the motor should start in standalone mode. I just tried doing that in lab and was very smooth excersize.The procedure is part of  EVM user guide http://www.ti.com/lit/ug/slou393c/slou393c.pdf

    Thanks,

    Jasraj

  • Hello Jasraj-san,

    Referring the SLOU393C user guide, their is a description that VCC should never exceed 18V for DRV10975EVM. I could not find the description to apply more than 22V when programming the EEPROM. Is there a description ?
    I will receive the evaluation kit in one or two days, so I will try it myself.

    Best Regards,
    Kawai
  • Kawai-san
    That is for operational condition. For eeprom programming we need 22V min.
    When we write eeprom, even GUI will also ask to set the voltage min at 22V.
    Thanks,Jasraj
  • Hello Jasraj-san,

    I understand, thank you for the information. Please let me evaluate the EVM and allow me to ask you for further help if I could not spin the motors. I will verify your posts after successful operation.

    Best Regards,
    Kawai
  • Kawai-san,

    I hope you are able to spin the motor with the suggestions.

    Jasraj
  • Hello Jasraj-san,

    Thank you for your continuous support and my apologies for my delay to reply.

    I was able to spin the motor normally. I had went through the quick start guide, however, this document is not describing about EEPROM Key and eeWrite. It may be better to add the eeprom writing procedures for users to use the EVM easier. Also what I faced is that eeprom were not able to write with VCC at 22.5V. My EVM required 22.7V for correct programming. DRV10975 absolute maximum ratings of VCC is 23V, so some user may not try increasing the VCC voltage for EEPROM writing.

    Best Regards,
    Kawai