SUCCESSIVE APPROXIMATION TYPE A/D CONVERTER

摘要

A more significant DAC (21) and a less significant DAC (22) have a plurality of capacity elements (c1-c4, c6-c9) for which capacity value is weighted with a binary ratio, which are constituted so that one end of each capacity element is connected to a common node and the other end thereof is alternatively connected to either a first voltage or a second voltage, and the more significant DAC and the less significant DAC have combined binding capacity (23). A more significant DAC control circuit (7) inputs alternatively either a compensation control signal or a digital signal outputted from a successive approximation comparison circuit (5) into the more significant DAC. The less significant DAC (22) has at least one variable capacitance element (ct1, ct2) of which one end is connected to the common node and of which the other end is alternatively connected to either the first voltage or the second voltage according to the more significant digital signal bit outputted from the successive approximation comparison circuit (5) into the more significant DAC (21).