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OPT8241: A problem with the output image of OPT9221

Part Number: OPT8241
Other Parts Discussed in Thread: OPT9221

Hi guys:

          I made a broad which was refer to the OPT8241-CDK-EVM board. Now I'm trying to configure OPT9221 through the I2C and everything is OK except one problem. When I tried to enable De-Aliasing there were many stripes on the image.This situation is not appear when I use  OPT8241-CDK-EVM board.

           I cannot find the reason after checking the hardware and changing the Register. So,can you help me please.Thanks!

Regards,
Chris

  • Hi Chris,

    There are several registers required to turn on dealiasing. Could you please list out all the registers that you changed?

    See section 7.3.7.2.1 of the OPT9221 datasheet. Additionally, please ensure that phase_corr_1 and phase_corr_2 have been correctly programmed as described in section 7.3.8.1

    Best Regards,
    Anand
  • Hi Anand:
    Thank for your help!
    There are the registers :
    {0x5880, 0x000001},
    {0x5883, 0x000026}, /* TG: SUB_FRAME_CNT_MAX = 2,
    QUAD_CNT_MAX = 6 */
    {0x5CB2, 0x000AAA}, /* DE: FREQ_RATIO = 2730(f1 * 4096 / f2) */
    {0x5CB3, 0x000A00}, /* DE: DELAY_FB_COEFF = 2560(f1 * 1024 / 24MHz) */
    {0x5882, 0x0208D5}, /* TG: PIX_CNT_MAX = 133333 */
    {0x5C28, 0x000000},
    {0x5C02, 0x900C42},

    {0x5C03, 0x101800},

    {0x5880, 0x000000},

    // Modulation Frequency settings: default of 24 MHz
    {0x580C, 0x0D8000},
    {0x580F, 0x00052A},

    {0x5802, 0x00001C},
    Best Regards,
    Chris
  • Hi Chris,

    Could you please confirm that you write to the intg_duty_cycle register at the end of the sequence? If not, could you set the intg_duty_cycle explicitly as the last step and check?

    - Anand
  • Hi Anand:
    Yes,I have write the intg_duty_cycle register. If i do not write the follow registers in my board,the output image of OPT9221 is right.But the situation is not appear in OPT8241-CDK-EVM board .
    {0x5883, 0x000026},
    {0x5CB2, 0x000AAA},
    {0x5CB3, 0x000A00},
    {0x5882, 0x0208D5},
    {0x5C28, 0x000000},
    {0x5C02, 0x900C42},
    {0x5C03, 0x101800},

    Best Regards,
    Chris