• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 45 subscribers
  • Views 458 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DAC082S085 component failure

Callan Brown
Prodigy 10 points
Other Parts Discussed in Thread: DAC082S085

Hello,

I'm working on a project using an atmega1284P using the Arduino IDE to program. I'm simply trying to set an analog value from 0-2.048VDC to a compact high voltage module (EMCO CA10P-5R) progamming input. I am using the reference voltage (2.048VDC) that the high voltage module provides.

The DAC seems to work for a while, perhaps hours, then I hear a POP and the voltage outputs go very low (some small amount above 0). Using a thermal camera I can see the device has failed and is burning up. This has happened 3 times so I'm quite sure this has to do with the conditions on my board. Can I ask about these things:

  1. Is the unbuffered V_refin a problem? should I put a voltage follower in between my reference voltage and V_refin? The datasheet for the high voltage module simply says "2.048V, up to 1mA" for the reference.
  2. I don't currently have a 10uF tantalum capacitor bypassing the power rail. I do have a 0.1uF cap on this and every other chip on the board.
  3. Is it possible it's succumbing to ESD? The high voltage modules produce 500V and -1500V, although the outputs are several centimeters away from the DAC.

Again, it seems to work for some time before this happens. Thanks

  • 0
    TI__Genius 16890 points

    Hi Callan,

    Items 1 and 2 will not cause a failure like this.  Most likely the high voltage is somehow getting to the DAC.  A high voltage that is sustained like the CA10P-5R would be able to provide would destroy the DAC082S085.  You will need to find the path that it is taking to the DAC.  Are some of the traces too close to each other?  Is there dust or other contaminants on the board that the electricity could use as an arc path?  Any of the pins are possibilities. 

    Mike