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.
I am currently having troubles with the monotonicity of the DAC7613. As I step the DAC one bit at a time, its output jumps back and forth between 2.5 and 2.8V. My VREFH is +3.3V and my VREFL is +1V. The VSS pin is connected to ground.
When I reset the DAC, its ouput goes to +1V as it should (RESETSEL is low); however, when I write a 001(hex) to the input register, the DAC's output jumps to 2.5V. As I continue to increment the input register, the output voltage bounces around without any apparent pattern. Any suggestions as to why it may be doing this? Have I missed something vital in the data sheet?
Could you post an oscilloscope picture showing this behavior? Is the data glitching to a voltage range of 2.5V-2.8V and then stabilizing to the correct code or is it outputting the output showing the wrong value? My nature of the DAC's design, you will see some glitching across major carry transitions but the output should stabilize quickly to the appropriate output code.
As for your second concern, you may having a timing issue. Double check that you are meeting the setup (DS) and hold (DH) timings for the parallel interface.
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Tony Calabria:
Thanks for your response. The output of the DAC is stabilizing to incorrect voltages between 2.5V and 2.8V i.e. 001(hex) gives 2.5V(stable), 002(hex) gives 2.65V(stable), 003(hex) gives 2.78V(stable), 004(hex) gives 2.63V(stable), 005(hex) gives 2.72V(stable), etc.
I believe that I am meeting the setup and hold times for the parallel interface. After writing to the input register, I read back from the input register each time to confirm that it was written correctly. The read back value seems to consistently match the previous write value.
In reply to Zack Bomsta:
Double check your reference values. Try tying VrefL to ground for preliminary testing to see if as you count up codes, the DAC responds as expected. You may also want to check the individual bits on the parallel bus using an O-scope to verify you are writing the data word that you think you are in your code.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry��s largest sales/support staff.