I am evaluating the AD7176-2 using a custom PCB with PIC24 microcontroller. I run into a strange problem that if 1Vpp and 2Vpp sinusoidal waves are applied to the input, the outputs variate from -800~900mV and -1400~1900mV.
I wonder if I did anything wrong to the hardware to get this error? The AVDD and AVSS are +2.35V and -2.35V respectively. The reference output is 2.5V with reference to AVSS. The source is generated from Agilent 33220A and is buffered before connecting to the inputs. Please advise some tips in order to perform troubleshooting.
Thank you ,