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DRV2604L: DRV2604L and DRV2604, Open loop setting

Part Number: DRV2604L
Other Parts Discussed in Thread: DRV2604

Hi Arthur-san,

This is related the following E2E session.

https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1049941/drv2604l-output-issue

Customer try to consider about open loop. because they cannot find solved method for the issue with closed loop setting.

Could you please review the customer setting for open loop? (frequency = 163Hz)

<DRV2604L>

0x1A[7] N_ERM_LRA: 1

0x1D[0] LRA_OPEN_LOOP: 1

0x1F[7:6]  AUTO_OL_CNT: 2 Default

0x1F[5] LRA_AUTO_OPEN_LOOP: 0 Default

0x1F[4] PLAYBACK_INTERVAL: 0 Default

0x20[7:0] OL_LRA_PERIOD: 3E=163Hz

0x22[7:0] LRA_PERIOD: 3E=163Hz

 

 <DRV2604>

0x1A[7] N_ERM_LRA: 1

0x1D[0] LRA_OPEN_LOOP: 1

0x22[7:0] LRA_PERIOD: 3E=163Hz

★ DRV2604L has address 0x1F and 0x20, however DRV2604 doesn't have those address.

   In case of DRV2604-null, how should they set the frequency setting? Is it OK, address 0x22 only?

Thanks

Mukuno

  • Hello Mukuno

    The settings seem to be fine, but I will verify with Design engineer tomorrow about the missing/differing registers in the DRV2604 and how that will affect application.

    Best Regards,

    Carson

    LPA Applications Engineer.

    Also is there a datasheet for the actuator that can be shared?

  • Hello,

    So after discussing with designer, the problem here is that only way to define open loop frequency in the DRV2604 is to go by

    Meaning you would have to use the PWM input to drive the output. So in digital mode open-loop frequency can tried to be set through drive_time parameter but very much restricts the flexibility.

    In the DRV2604L the 0x20 register was added to resolve this issue when using digital playback

    Best,

    Carson

  • Hi Carson-san,

    Sorry, we don't understand exactly about your comment.

    Is it meaning, they don't need the setting to  0x20[7:0] and 0x22[7:0] for open loop?

    Could you please let me know about the address that they should be change the register value from default for open loop operation?

    <DRV2604L>

     ・0x01[2:0] MODE3 (PWM input and analog input)

     ・0x1A[7] N_ERM_LRA: 1

     ・0x1B[4:0]  DRIVE_TIME19(=166Hz)

     ・0x1D[0] LRA_OPEN_LOOP: 1

     ・0x1D[1]  N_PWM_ANALOG0 (PWM input)

     ・0x1F[7:6]  AUTO_OL_CNT: 2 Defult

    0x1F[5] LRA_AUTO_OPEN_LOOP: 0 Defult

    0x1F[4] PLAYBACK_INTERVAL: 0 Defult

    0x20[7:0] OL_LRA_PERIOD: 3E=163Hz ←not need setting for open loop?

    0x22[7:0] LRA_PERIOD: 3E=163Hz ←not need setting for open loop?

     

    <DRV2604>

     ・0x01[2:0] MODE3 (PWM input and analog input)

    0x1A[7] N_ERM_LRA: 1

     ・0x1B[4:0]  DRIVE_TIME19(=166Hz)

     ・0x1D[0] LRA_OPEN_LOOP: 1

     ・0x1D[1]  N_PWM_ANALOG0 (PWM input)

    0x22[7:0] LRA_PERIOD: 3E=163Hz ←not need setting for open loop?

    Thanks

    Muk

  • If you are using PWM on either then 0x20 is irrelevant to setting the output frequency. It will be based on inputted PWM frequency

    For DRV2604L when using digital input you can control open loop frequency through 0x20 register

    For DRV2604 open loop and digital input can only be set through the DRIVE_TIME parameter

  • Again, Could you please let me know about the address that they should be change the register value from default for open loop operation?

    For each devices (Is my understanding correct?)

    DRV2604

    >0x1B[4:0]  DRIVE_TIME : they have to change to their setting

    DRV2604L

    >0x1B[4:0]  DRIVE_TIME  : they have to change to their setting

    >0x20[7:0] OL_LRA_PERIOD: 3E=163Hz   : they have to change to their setting

     

  • Also, please let me know about the following registers.

    Other registers, like 0x1A, 0x1D and 0x22

    They tried to adjust 0x1B only with DRV2604-null, the device didn't work with adjusting 0x1B only.

     Could you please let me know about "all" address that they should be change the register value from default for open loop operation? 

     <DRV2604>

    0x1A[7] N_ERM_LRA: 1

    0x1D[0] LRA_OPEN_LOOP: 1

    0x22[7:0] LRA_PERIOD: 3E=163Hz

    0x1B[4:0]  DRIVE_TIME1A=161Hz

  • For DRV2604:

    After doing some testing myself, if you want to use DRV2604 in LRA Open-Loop mode then you set Bit0 in 0x1D, but you cannot use digital playback as I might have previously suggested and control the frequency by DRIVE_TIME[4:0], the only way to control frequency is by using a PWM input. Also writing to 0x22 will also not work so PWM input is only way for frequency control in open loop for this model of chip vs the DRV2604L having those extra features.

    Best Regards,

    Carson

  • Thanks, Carson-san

    Is my understanding correct?

    DRV2604L can digital playback. (Also they can use PWM input)

    DRV2604-null cannot  the digital playback, it have to use PWM input for open loop.

    0x1F and 0x20 are for DRV2604L only to use digital playback. 

    Customer is using both DRV2604 and DRV2604L for thier products. If they will use both device with same software, they need PWM input.

    If they will access to 0x1F and 0x20 of DRV2604 that is not described in datasheet with same software for both devices controlling, Is is any problem? 

    For example, they access and write to 0x1F and 0x20 in DRV2604 as below, how will the DRV2604-null work?

    0x1F[7:6]  AUTO_OL_CNT: 2 Defult

    0x1F[5] LRA_AUTO_OPEN_LOOP: 0 Defult

    0x1F[4] PLAYBACK_INTERVAL: 0 Defult

    0x20[7:0] OL_LRA_PERIOD: 3E=163Hz 

    Thanks

    Muk

  • Hello,

    I think they just dont exist but I can test in lab, but its unlikely writing to undescribed registers would cause any complications but it wont make make DRV2604 work like the DRV2604L. Despite the naming convection the parts are different it several ways.

  • Hello

    Customer understand,  it wont make DRV2604 work like the DRV2604L.

    However, They have to use both device, because they have WW supply issue of ICs.

    Is it meaning, even if they access the hidden register(0x1F and 0x20 etc), the device operation will not change?

    > I think they just dont exist

    Thanks

    Mukuno

  • Hello,

    These are not hidden registers to my knowledge but I will ask designer when he is available.

    Best Regards,

    Carson

  • Hello,

    Digital Interfaces are different and those registers aren't available.

    Best Regards,

    Carson