DLPA3005: Power Sequences

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Replies: 9

Views: 135

Part Number: DLPA3005

Hello,

I have an question regarding our developing DLP4710/DLPC3479/DLPA3005. DLPA3005 signals on our designed board looks like working fine. However, the power sequences looks incorrect. Can we allow below procedure?.

Datasheet shows :

Regards,

Uryyy

9 Replies

  • Hi Uryyy,

    It looks like PROJ_ON may be glitching high before SYSPWR is ready which is causing some unexpected and slow rising voltages. Is there anything else on the PROJ_ON rail that could be causing that glitch? Additionally has this been seen on just one of your boards or multiple boards?

    Thanks,

    Kyle

  • In reply to Kyle Rakos:

    Hi Kyle,

    Are you saying below circle? If so, we have to improve this point.

    Regards,

    Uryyy

  • In reply to Uryyy:

    In spite of PROJ_ON=OFF(Low), DLP4710EVM-LC is also same sequence.

  • In reply to Uryyy:

    Hello Uryyy,

    Yes, I am thinking it's possible the glitch circled on PROJ_ON could inadvertently be causing some issues like having the other voltages come up before the SYSPWR is stable. In the waveform where PROJ_ON is low the entire time do you see a glitch on it as well?

    Thanks,

    Kyle

  • In reply to Kyle Rakos:

    Hi Kyle,

    Yes, both of our designed board and 4710EVM are SUP_5P0V/SUP_2P5V=High after SYSPWR while PROJ_ON is low..

    Regards,

    Uryyy

  • In reply to Uryyy:

    Hi Uryyy,

    In the waveform where PROJ_ON is low the entire time do you see a glitch on it as well? Could you please share that waveform? I would recommend seeing if we can't eliminate the glitch. Perhaps you could temporarily add a capacitor on PROJ_ON to see if it filters out the glitch and the problem goes away. That could help us determine if it's actually the cause.

    Thanks,

    Kyle

  • In reply to Kyle Rakos:

    Hi Kyle,

    These are DLP4710EVM-LC power signals.

    Enlarged :

    Regards,

    Uryyy

  • In reply to Uryyy:

    Hi Uryyy,

    It is possible that the startup diagram is incorrect and SUP_5P0V and SUP_2P5V actually come up with SYSPWR. Please let me continue to look into this and I'll get back to you next week.

    Thanks,

    Kyle

  • In reply to Kyle Rakos:

    Hi Kyle,

    You can reproduce on EVM. I look forward to wait a good result.

    Regards,

    Uryyy