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DLPA3000: Dule DLPC3479 +DLPA3000 DMD HV voltages output issue

qiaoguanliang
Prodigy 20 points
Part Number: DLPA3000
Other Parts Discussed in Thread: DLP4710LC, DLPC3479

hello TI experts:

after DLPA3000 auto-initializing, HOST_IRQ is low, INT_Z generates one pulse(I think it is not a fault), then DMD HV Voffset  Vrst is low, 

Q1:  is it normal according the firmware what is in the flash?

Q2: which IIC command can make normal value for the HV Voffset  Vrst ?  

thank you

  • 0
    TI__Expert 5445 points

    Hello,

    Can you provide scope shots of the following on startup?

    • Vbias, Vrst with INT_Z and RESETZ

    Is this issue occurring on multiple systems? Has the issue happened before or is it just starting? This will give us better understanding of what is happening in your system.

    Best,
    Maximus

  • 0 in reply to Maximus Rusi
    Prodigy 20 points

    Can you provide scope shots of the following on startup?==the first scope shots above is happening on startup.

    Is this issue occurring on multiple systems? ==No, we did the PCBA with combination 2 DLPC3479+DLP4710LC+DLPA3000. we only have 2 PCBA. I designed the schematic by referring to EVM4710 sch.

    Has the issue happened before or is it just starting? ==it is just starting. we tried some commands to enble DMD HV Vbias, Vrst output normal value but failed.

    because the Sequence waveform of INT_Z and RESETZ is different from the datasheet of DLPA3000 Power Sequence Normal Shutdown Mode and Power Sequence Fault Fast Shutdown Mode

  • 0 in reply to qiaoguanliang
    Prodigy 20 points 
    Continuing from above, I CAN NOT find the commands to set DMD_EN to 1. 
    thank you.
  • 0 in reply to qiaoguanliang
    TI__Expert 5445 points

    Hello, 

    The scope shots you mentioned above do not show Vbias, if youc ould take them with Vbias instead of Vofs that would be great.

    To answer your question about the dmd en please see the commands below:

    # Addr write
    W 36 eb 01 00 00 01 00

    # Write Value to register
    W 36 ec 93

    Best,

    Maximus

  • 0 in reply to Maximus Rusi
    Prodigy 20 points

    thank you 

    It is the overvoltage of VLED which made DMD HV output switch off.  I changed the VLED's output capacitor value lower than ILLUM_A_VIN(DLPA3000 PIN30) input, THE DMD HV output  value become normal.

  • 0 in reply to qiaoguanliang
    TI__Expert 5445 points

    Hi, 

    Is your issue resolved then? Glad the output has returned to normal.

    Best,

    Maximus