I'm trying to evaluate AD5791 on the ADI evaluation board EVAL-AD5791SDZ.
I use following settings:
- power supply: VCC=+5V / VDD=+12V / VSS=-12V
- external reference VREF=+5V (so DAC output range is +/-10V)
- serial communication with an external SPI generator (frequency 1MHz)
- LDAC is tied low (jumper LK4 inserted)
Communication with DAC is correct because I can change Control register value (example bit DACTRI) and I see change on DAC output.
After board power-up, I send value 0x200012 to Control Register to disable DACTRI and OPGND. DAC output voltage is now at VREFN (-10V in my case).
But the problem is when I try to change the DAC value (code 0x1000FF by example), the output voltage remains still to VREFN. I have also try to use other code but the output doesn't change. Is there any other configuration that I missed?
Thanks for your help.