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DLPC120-Q1: DLPC120-Q1 and DLP3030-Q1 HUD product has some problem in development

Part Number: DLPC120-Q1
Other Parts Discussed in Thread: DLP3030-Q1,

I use DLPC120-Q1 and DLP3030-Q1 to develop a HUD product,our schematic diagram is the same as the reference design 2514132b, but the PCB layout is totally different from the reference design. when we used the ACP and CA310 do calibration with the PGU,I found there were gaps in output brightness ,and we couldn't remove the gaps by adjusting coarse combination parameters. we used the TI EVM board do calibration with the PGU,there  was no problem. I download the calibration file to our HUD board, and set the brightness by ACP,I find that the HUD  low brightness value in DM mode , is brighter than  high brightness value in CM mode. and the color in low brightness has deviation and jitter .  We cann't  solve the problem ,what's wrong with our HUD board? 

  • Hello Wenwen,
    I have a few questions that will help debug this issue.

    Which version of Automotive Control Program are you using? Please use 1.4.2.57, as the previous versions have had issues with the CA-310 during calibration.

    Did you make sure to adjust the variable resister to adjust the photodiode response on your new board? In our schematic this is R58. This value will need to be adjusted so the photodiode response saturates properly. The value will change for all optical systems, as it depends on how much light is incident on the photodiode, and can cause the issues you are seeing if not properly adjusted. It sounds like your resister might be adjusted too high. A typical value is between 300-1000 ohms, but measure the potentiometer value on the EVM board and adjust your HUD board to match it.

    Hopefully this can help.

    Best Regards,
    Jackson
  • Hello Jackson,
    Thank you for help! I use ACP 1.4.2.57 , and I measured the R58 value on the EVM board is 3.3KΩ, we set the same value on our board. I'll try to change the potentiometer value to 300-1000 ohms.
  • Hello Jackson,
    I try to change the potentiometer value to 300-1000 ohms,it cause other issues :the brightness doesn't change when I set the brightness value >10000 and higher. I think , it maybe the power and GND noise casue the issues .The inductor L2 has loud noise when it driver the LEDs, it cause the P12V_HC_6 power noise 600mV,and the GND noise 120mV. Especially,we didn't separated the PGND and GND, we used a common GND. Do you think it cause the problem?
    Think you!
  • Hi Wenwen,

    If the EVM board is working with the potentiometer at 3.3kohms, then this is probably a good position.

    Having all the grounds on a common plane may cause issues and excess noise. This ground plane noise may certainly limit brightness output at low levels. Where is the 12V power to the board coming from? If there is electrical noise on the input this may couple through the board. Have you looked at the noise on the input?

    Regards,
    Jackson
  • Hi Wenwen,

    Please let me know if you identify the source of noise on your board layout or have any further questions with your layout or the EVM layout.

    Regards,
    Jackson
  • Hi Jackson,
    I didn't test the noise on my board,beacause I didn't have a PGU. We will design a new PCB layout in this month, then I'll send you to check. Thank you!
  • Thanks for the update,

    Feel free to ask any follow up questions here or create a new thread.

    -Jackson