I'm using AD4020 for DC input measurement by implementing Figure 36 of AD4020 datasheet. Implemented schematic is below
But i'm getting non-zero readings which gives 0.25V reading by considering only MSB 15 bits and converting same to voltage by multiplying reading with 7.63uV. ie i'm getting readings like "7FB8x" as MSB. W.r.t to the schematic shared, what could be the problem, does this IC have some offset ? Please confirm single-ended DC input support for this part.