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DLP4710LC: Schematic review of DLP4710 Board

Shyam Daram
Expert 1255 points
Part Number: DLP4710LC
Other Parts Discussed in Thread: DLPC3479

I have designed my own DMD board schematic for which i need help in schematic review 

I wish to make this board in compatible with DLP4710LC EVM so that i can test standalone with existing dlpc baords

Attached is the schematic, this is exctly made inline with DLPC evm including all possible signals

  • +1
    TI__Expert 3905 points

    Hello Shyam,

    Welcome back to the E2E forum!

    Our schematic review feedback:

    1. On the connector side, we recommend using 0.1uF capacitors rather than 2.2uF on Voffset, Vreset, Vbias, and Vflash.
    2. On the connector side, Vbias with its 18V rail is missingfrom the schematic. Voffset is listed twice.
    3. On the DMD side, we recommend using 0.22uF capacitors rather than 2.2uF on Voffset, Vreset, and Vbias.
    4. On the DMD side, we notice that VDDI pins 1-8 are not connected to anything.
    5. On both the connector and DMD side, VDD and VDDI should be 3.3V, not 8V.
    6. Note: On the DMD side, VDD and VDDI can be split, but TI's design has them as a single rail.
    7. On the DMD side, VDD has a total of 4 capacitors, each 0.22uF. Your design has 6 for each VDD and VDDI, each 0.1uF.

    Best,

    Maxine

  • 0 in reply to Maxine Cabrasawan
    Expert 1255 points

    Thanks verymuch for your points, the reason for these mistakes , i dont have the schematic of DMD board, i tried to reconstruct from kit i have.

    I have modified schematic with all changes proposed, i have few more doubts in Final_Schematic

    1. What is Pin 37, i cant see V_FLASH going anywhere, as in some other thread , engineers confirmed the Flash IC on the DMD board is not being used, so i assume i can remove the rail, so i removed, it will be open pin now

    2. Voltage sources coming from pin i have renamed so that they are not directly shorted to pins( these are aliases), so the approach now, is rail is created post capacitors and then given to DMD side.

    3. Can you please recheck from signals side also to see if i have misplaced any signals ? the connector i have anyway i have directly taken from DLPCEVK blue board.

  • 0 in reply to Shyam Daram
    TI__Expert 3905 points

    Hello Shyam,

    1. Pin 37 is V_FLSH is needed to power the SPI flash. There are connections to V_FLSH on the DLPC3479. If SPI is being used, then V_FLSH is necessary. Please refer to the DLP4710EVM-LC schematic.

    2. Can you clarify what you mean?

    3. The signal placement appears correct. Is is the DLPCEVK blue board the DLPC3479 controller board?

    Best,

    Maxine

  • 0 in reply to Maxine Cabrasawan
    Expert 1255 points

    1. This i have confirmed with few TI engineers in a personal chat, where they have clearly mentioned that the Flash IC mounted on DMD board are not being used and the program is being flashed on DLPC boards only

    2. Please see my final schematic, to understand what i am trying to say

    3. DLP4710EVM-LC Evaluation board | TI.com is the board i am referring to

  • +1 in reply to Shyam Daram
    TI__Expert 3905 points

    Hello Shyam,

    1. If you are not using SPI, then V_FLSH may not be necessary and can be left unconnected.

    2. Placement of capacitors close to the DMD is critical for proper operation and reliability.

    3. Your signal placement appears correct.

    Best,

    Maxine