Hi everybody, I'm reading about sigma delta adc, the base theory. I've read about the first order modulator and now the second order, but I have a problem (maybe stupid) with a phrase of my book (Data Converters by F.Maloberti), when he describe the 'passage' from first order to second order. He says: "Better performances and features are secured by using two integrators around the loop thus forming a second-order modulator as shown in the conceptual scheme of Fig. 6.11 (a). Since the use of two integrators in a feedback loop can cause instability, it is necessary to dump one of the two integrators by using one of the two options represented by the dotted lines of Fig. 6.11 (a)." (Fig. 6.11 (a) is attached) Why two integrators in the loop can cause instability? I can't see why... Thank you very much!