I driving EVAL-AD7983-PMDZ by Unipolar, Single-Ended sinusoidal signal (Vpp=4V, Voffset=2 so Vmin=0, Vmax=4).
R2 and R4 were removed from the EVAL-AD7983-PMDZ PCB because they give the additional useless voltage offset:
I see that samples are incorrect. Even if V+ is connected to the Gnd I see the offset:
I tried to slow down (to 1MHz SPI clk) the SPI interface but it does not help. SPI looks as usual:
What could be a reason for this ADC behavior?