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DRV2667: Problem with distortion after playing ram waveform

Part Number: DRV2667

Hi.

We are suffering from weird waveform problem. If we run ram waveform we get 5-10ms peak after the control ends. First I tough that the problem is with the ram page having non-formatted data or running it over. However this isn't the case, as I padded the pages with 0 and the problem still persist and with all content we test this with (different sizes, etc). Is this some mode change issue from ram mode to analog, or something?

We are using the SDK for DRV2667EVM-CT RevA.

  • Hi Maash,

    Welcome to e2e.
    Can you send your detailed EVM configuration procedure so we can try to replicate this form our side?

    Best regards,
    -Ivan Salazar
    Applications Engineer - Low Power Audio & Actuators
  • Hi.

    So this is just a test, so we are using the DRV2667EVM-CT_Firmware_v1.1. We've changed the (in WaweFormData.c) mode 2 two-tone structure to contain new waveform and the header structure to match the size.

    const unsigned char TWOTONE[] = {
    REG_0,
    0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x01, 0x03, 0x06, 0x0a,
    0x0f, 0x14, 0x1a, 0x21, 0x27, 0x2d, 0x32, 0x37, 0x3a, 0x3d, 0x3f, 0x3f, 0x3f, 0x3d, 0x3b, 0x37,
    0x32, 0x2c, 0x26, 0x1f, 0x17, 0x0f, 0x07, 0xff, 0xf7, 0xef, 0xe7, 0xdf, 0xd8, 0xd2, 0xcc, 0xc8,
    0xc4, 0xc2, 0xc0, 0xc0, 0xc0, 0xc2, 0xc5, 0xc9, 0xcd, 0xd3, 0xd9, 0xe0, 0xe7, 0xef, 0xf7, 0x00,
    0x07, 0x0f, 0x17, 0x1e, 0x25, 0x2b, 0x31, 0x36, 0x3a, 0x3d, 0x3f, 0x40, 0x40, 0x3f, 0x3d, 0x3a,
    0x36, 0x31, 0x2c, 0x26, 0x1f, 0x18, 0x10, 0x08, 0x00, 0xf9, 0xf1, 0xea, 0xe2, 0xdc, 0xd5, 0xd0,
    0xcb, 0xc7, 0xc4, 0xc2, 0xc0, 0xc0, 0xc1, 0xc2, 0xc5, 0xc8, 0xcc, 0xd2, 0xd7, 0xde, 0xe4, 0xec,
    0xf3, 0xfb, 0x02, 0x0a, 0x11, 0x19, 0x20, 0x26, 0x2c, 0x32, 0x36, 0x3a, 0x3d, 0x3f, 0x40, 0x40,
    0x40, 0x3e, 0x3c, 0x38, 0x34, 0x2f, 0x29, 0x23, 0x1d, 0x15, 0x0e, 0x06, 0x00, 0xf8, 0xf0, 0xe9,
    0xe2, 0xdb, 0xd5, 0xd0, 0xcb, 0xc7, 0xc4, 0xc2, 0xc0, 0xc0, 0xc0, 0xc1, 0xc3, 0xc6, 0xca, 0xce,
    0xd3, 0xd9, 0xde, 0xe4, 0xea, 0xef, 0xf4, 0xf8, 0xfb, 0xfe, 0xff, 0x00, 0x00, 0x00, 0x01, 0x01,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

    const unsigned char DRV2667_HEADER[] = {

    ...

    0x02,0x00,0x02,0xff,0x1, // Waveform #15 Two-Tone

    ...};

    Also the other size references(in haptics.c -> haptics_init() ) are changed to match the size of the thing. We've also tested with other waveforms and same difference.

    ******************

    I would also like to point out that the glitch in the waveform isn't affected by the waveform amplitude or gain. We've tested with few waveforms (with different lenghts)and gain settings and the clitch stays the same. It's also not running past the ram area, as I've tested with another pattern in next ram section, and it doesn't affect the glitch either. Also we see sight differences between two HW we have. 

  • Hi, Maash,

    Regarding your measurement in your oscilloscope, could you compare your results in AC-coupled and DC-coupled modes? Do you get some differences?

    Additionally, do you have the same results in Demo mode?

    Best regards,
    Luis Fernando Rodríguez S.
  • Hi, Maash,

    Do you have any feedback about this? Could you take a look at my questions above?

    Thank you.

    Best regards,
    Luis Fernando Rodríguez S.
  • Hi.

    The wave generation patterns do not create this effect.

    We'll have to check the original two tone pattern with ram format if it causes this same effect. I do not have access to HW to check this untill next thursday. But I'll check it then.

  • Hi,

    Thank you, Maash. I strongly recommend to verify with the different scope modes (DC-coupled and AC-coupled modes) and see if there are differences. We got a similar effect with our EVM and our scope on AC-coupled mode. Please let us know what you find next Thursday.

    Best regards,
    Luis Fernando Rodríguez S.
  • Hi, Maash,

    Excuse me, did you have a chance to take a look at this? Do you have any update?

    Thank you.

    Best regards,
    Luis Fernando Rodríguez S.
  • Hi, Maash,

    I will close this issue for now. But please feel free to provide a feedback if you could solve this issue. Also you may ask for more information about it in case you require it. We will be glad to help you.

    Best regards,
    Luis Fernando Rodríguez S.