DRV2605: Cannot get haptic feedback either with LRA or Piezo

Part Number: DRV2605

Hello,

I am trying to get a haptic feedback either using LRA motor with DRV2605, or using piezo with DRV2605/DRV2700 (based on application report SLOA255).

When using just LRA, the haptic feedback is barely noticeable. However, when the LRA is driven directly from a power supply, the feedback is strong.
When using the DRV2700 with a signal from DRV2605, there is no feedback can be felt. I also notice that the FB pin does not output 1.3V. Thus my PVDD signal is around 10V instead of 65V.

Attached is the schematics of the haptic driver circuit. The selection between Piezo or LRA is done using J1 and J2 jumpers.

LRA motor - 1020-15-003-001 (www.digikey.ca/.../j2rmtd)
Piezo - Z63000Z2910Z 1Z 2 (www.digikey.ca/.../j2rm8v)

I am looking for any possible recommendation.

Thank you.

Regards,
Leon

17 Replies

  • In reply to Ivan Salazar:

    Ivan,

    I replaced the C13 cap to 08051C104K4T2A (100V, X7R, 10% 0805). The only issue is that it is 0805, so I had to do some adjustment was required on the board. However, the connections are solid.
    The input DRV2605 stage is disconnected by removing jumpers on J1 and J2. All other devices (except the microcontroller) are disabled by using their respective EN pins.

    After powering the circuit the results did not change. The same results are observed.

    Unfortunately, it would be extremely hard to power the DRV2700 from a separate power supply. It would require trace cutting, component lifting, and wire-up steps. I am not sure if that would be a good test.

    Regards,
    Leon

  • In reply to Leonid Hrapunsky62:

    Leon,

    Is there a chance that you could capture the signal at SW pin? I would like to know if this pin is switching or not.
    How is your whole system powered? By batteries or by external DC power supply? Can you power up the whole system (other ICs, uC and DRV2700) with a DC power supply? I just would like to know if current capacity is being an issue here.
    Trying different units of DRV2700 is possible? This could help to identify if the device could have got damaged.

    Last, one additional thing I would like to ask: When you test DRV2605 and it operates fine, is DRV2700 enabled or disabled? I would like to know if enabling DRV2700 could affect other devices in the system due to high current drain.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • In reply to Ivan Salazar:

    Hi Ivan,

    Attached is the screenshot of SW pin during operation. Please note at this stage the DRV2700 is only powered and enabled. No piezo connected and no input provided.

    The circuit is powered DC power supply and its limit is maxed (3A).

    I did try a few other boards before I contact forum. Unfortunately, I see sort of the same issues.

    When DRV2700 is powered and enabled, it is significantly affecting the supply rail (in some boards the supply drops to 4V and other to 3V). Please see the attached power circuit as well.

    Regards,
    Leon

  • In reply to Leonid Hrapunsky62:

    Hi Leon,

    I apologize for the late reply.
    It seems like the device is having a hard time trying to start it operation. It would be good to know if SW pins are switching, this would let us know if the boost converter is operating.
    Have you tried with different inductors on L2? It seems like the inductor and the down converter are correctly spec in terms of current but just want to know if changing the inductor could affect the behavior.
    Current from power circuit should not be an issue as DRV2700 is even able to be supplied by USB 5V which is around 500mA max.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • In reply to Ivan Salazar:

    Hi Leon,

    I wanted to ask one more thing. Can you please capture the output of the 5V regulator without DRV2700 in the system? Or when it is disabled?
    And also when the device is present and enabled? (I'd like to see the transition between device disabled and then enabled) This would show if VDD is directly affected by the SW switching.

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • In reply to Leonid Hrapunsky62:

    Hi Leon,

    We haven't heard back from you. We are assuming that you were able to solve your problem. If no, just respond to Ivan's questions.

    Best Regards
    José Luis Figueroa
    Audio Applications Engineer
  • In reply to Ivan Salazar:

    Hello Ivan,

    I really apologize for long reply time. I was urgently dragged to a different project and I had to leave this project completely. I changed the 10uH inductor (IHLP2020BZER100M01) to 15uH inductor (IHLP2020CZER150M01). There is no change in performance.

    Any recommendations?

    Regards,

    Leon