Three-step circulation-type analog-digital (A/D) converter, carries out third operational step for adjustment of group capacitors charge

摘要

A three-step analog-to-digital (A/D) circulation- type converter includes an A/D conversion circuit and a capacitor group-circuit comprised of a number of group capacitors (C1-C7) with each group capacitor having a group electrode which is connected to the group signal line (5). During the third, or subsequent step of the A/D converter, a charge adjustment of each of the group capacitors (C1-C7) takes place on the basis of the output voltage of an op.amp. (3) by closing the second switching network (S11) when the first switching network (S10) is open, followed by initialization the integration capacitor (CF) through an integration-initialization circuit.