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Original question:

DAD1000 datasheet

DLP3000: DAD1000

Carlos Silva85
Expert 4915 points

Part Number: DLP3000

I have a couple of queries regarding the DAD1000.

The datasheet indicates the device has an internal 5V supply regulator (V5REG) that provides supply and reference to the internal logic, which is also output from the device with an implied max load of 30mA.

1)      Does this imply that the digital inputs of the DAD are tolerant of continuous drive (or pull-up) to 5V?

2)      Could this supply be used as a pull-up reference for the open collector outputs such as SCPDO?

Happy to discuss offline if it helps.

  • 0
    TI__Mastermind 28005 points

    Carlos,

    I believe that the DAD1000 is a Cinema part. I'll forward this question to them so they can assist you more thoroughly.

    Best Regards,
    Philippe Dollo

  • 0 in reply to Philippe Dollo
    TI__Intellectual 2580 points
    Carlos,

    I believe the DLP3000 has an integrated reset driver; so the use of an external reset driver (DAD1000 or DAD2000) should not be necessary.

    SCPDO is listed as "LVTTL" in the datasheet, implying 3.3V compatibilty. The datasheet also specifically indicates "1K pull up resistor to the 3.3-volt ASIC supply" for SCPDO.

    Regards,
    Gary
  • 0 in reply to Gary S
    TI__Expert 4915 points
    Thank you Gary.

    On a similar subject, would it be acceptable to pull-up DAD inputs and outputs when the DAD itself is unpowered? Would this be acceptable on a continuous basis? This was the reason for asking about the 5VREG output as it would be up only when the DAD is powered. The datasheet has absolute maximum for inputs of 7V, but is this acceptable continuously without damage?
  • 0 in reply to Carlos Silva85
    TI__Intellectual 2580 points
    Carlos,

    Regarding pulling up the pins while the part is not powered on.... In general, power could feed back through ESD protection diodes; so it is generally advisable to avoid doing that, unless the part is designed for that. I can look into that further with the original design team for the DAD1000, if necessary....


    Regarding whether it is okay to operate at absolute max continuously.... the datasheet has this note in the absolute maximum ratings section:

    † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute–maximum–rated conditions for extended periods may affect device reliability.


    The DLP3000 does not require an external reset driver (DAD); so I am not sure what the relevance is to the DLP3000. Also, I believe the DAD1000 is not used in any current designs; it is mostly used in DLP Cinema(R) and other, older designs. The DAD2000 is generally used in any newer applications requiring an external reset driver. What is the application that you are considering the DAD1000 for?


    Regards,
    Gary