Part Number:DAC8820
Tool/software:TINA-TI or Spice Models
I read through the DAC8820 pdf and Figure 42 describes a bipolar voltage generator (-10v to +10v). I transcribed this pdf in TINA and used a OPA277 because when I searched for OPA2277 it defaulted me to OPA277. I attached the TINA file here but it looks as if it is not going through to this site. I copied the pdf but with a few additions. I tied all of the digital inputs together and driving them with a 3.3v square wave. Vdd = 3.3v, wr=0, RS=3.3, LDAC = 3.3, RSTSEL =0, DGND and AGND are both tied to a common ground. Output is monitored at the op amp at Vout. I am getting roughly 0 to -VREF instead of -VREF to +VREF as what is written in the pdf. I also tried to attach a pdf image if the TINA file. Please help. I now see the TINA file is posted along with a pdf of the TINA file. I also reviewed the 3 videos. At the tail end of the video is another example of generating bipolar voltage, I will test it with TINA also. 
