I am driving my DAC8806 with an FPGA at 3.3v. Last week a GPIO pin on the FPGA quit working. It is connected directly to pin28(reset) on the DAC8806. I thought nothing of it as the FPGA has gone through a year of testing. I replaced the FPGA and through some more use, the same pin on the FPGA went bad in one day. That run on my PCB goes from pin to pin with no vias.
My configuration is as follows, I have a THS4011 connected directly to the DAC8806 as per your PDF. The THS4011( at -9v to +9v) then drives a OPA552(-9v to +40v). It all looks good under Tina.
VREF on the DAC8806 is -9v.
My goal is to generate what looks like a modified version of the upper part of a 0-30v sine wave or "mountain range". Since I can code 0V, do I really need the reset pin?
Do you have any idea as to why the DAC8806 kills my GPIO pin? I looked at it with an O-scope. and there is a little jitter at that pin when I turn the system on and off.
At $100 each for the FPGA, it can get expensive.
Thanks.
Regards,
Doug