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Question of DRV2604 for LRA auto resonance off

Jacob Kim
Prodigy 250 points
Other Parts Discussed in Thread: DRV2603, DRV2604, DRV2604L

Hello There

My name is Jacob and I am supporting Korea Mass Market customer as FAE.

 

One of Customer is applying DRV2603 and they had issue with Auto-Resonance function.

(When leaner motor was touched, the current went to 40mA up.)

 

Customer evaluated with DRV2604 with disable of Auto-Resonance function and solved this issue.

 

There is two question,

 

  1. Does DRV2603 support disable of Auto-Resonance function?  (I got answer from E2E forum)    

  1. If customer applies DRV2604 with LRA Auto-Resonance function off, Please share some guide aobut disable Auto-Resonance function.

 

Thank you

 

  • 0
    TI__Expert 8940 points
    Hi, Jacob:

    1. DRV2603 doesn't support driving LRA with Auto-Resonance disabled.

    2. DRV2604 use in open loop mode (LRA auto-resonance disabled)
    www.ti.com/.../drv2604.pdf
    it has some detail inside.
    -----------------------
    When using the PWM input in open-loop mode, the DRV2604 device employs a fixed divider that observes the
    PWM signal and commutates the output drive signal at the PWM frequency divided by 128. To accomplish LRA
    drive, the host should drive the PWM frequency at 128 times the desired operating frequency.

    In open-loop mode, the RATED_VOLTAGE[7:0] bit is ignored. Instead, the OD_CLAMP[7:0] bit (in register 0x17)
    is used to set the rated voltage for the open-loop drive modes. For the LRA, Equation 5 calculates the RMS voltage with a full-scale input
    signal.

    To configure the DRV2604 device in LRA open-loop operation, the LRA must be selected by writing the
    N_ERM_LRA bit to 1 in register 0x1A, and the LRA_OPEN_LOOP bit to 1 in register 0x1D.

    In open-loop mode, the reference level for full-scale drive is set by the OD_CLAMP[7:0] bit in Register 0x17. A
    mid-scale input value gives no drive signal, and a less-than mid-scale gives a negative drive value. For an LRA, a negative drive value results in a 180-degree phase shift in commutation.
    -----------------------------------------
  • 0 in reply to Peter Li79
    TI__Prodigy 250 points

    Thank you Peter

    We provided DRV2604 EVM to evaluate driving LRA with Auto-Resonance disabled, however Customer couldn't code MSP430 F/W to be disable Auto Resonance.

    Could you help to customer to get DRV2604EVM 's F/W(MSP430) of disable Auto Resonance?

    They need to check this function with DRV2604 EVM and will apply DRV2604.

  • 0 in reply to Jacob Kim
    TI__Expert 8940 points

    Hi, Jacob:

    I want to make sure which part you are going to use.

    is it DRV2604 or DRV2604L? these two parts are slightly different.

    can customer program the onboard MSP430?

    Thanks.

  • 0 in reply to Peter Li79
    TI__Prodigy 250 points

    Hi Peter

    Sorry for late resonpose.

    It is DRV2604, not 2604L.

    TI Disty will support MSP430.

    Thank you

  • 0 in reply to Jacob Kim
    TI__Expert 8940 points

    Hi, Jacob:

    here is the EVM user guide:

    here is the EVM firmware:

    DRV2604EVM-CT_REVA_P9-2012-12-29.zip

  • 0 in reply to Peter Li79
    TI__Expert 8940 points
    Hi, Jacob:

    as you can see from the user guide, it has some open loop mode (auto-resonance disabled) operations.
    also, TI disty FAE can look into the firmware (search "open loop") and find out how to configure DRV2604 to run in open loop mode.

    please let me know whether this can help the customer.
    Thanks.