| 摘要 |
PROBLEM TO BE SOLVED: To provide an AD converter having capacitive elements including a split capacitive element which implements a capacitance value adjustment for ensuring conversion accuracy in a compact circuit configuration.SOLUTION: The AD converter includes: an upper group of capacitors CU-G with terminals on one side connected in parallel to an upper common terminal; a lower group of capacitors CL-G with terminals on one side connected in parallel to a lower common terminal; and a subsidiary group of capacitors CS-G. The other terminal of each capacitor included in each capacitor group is connected to any of an input analog voltage, a reference voltage and a ground voltage via a switch group. Capacitors included in the lower capacitor group and subsidiary capacitor group are selected such that a combined capacitance value matches a capacitance value of the lowest capacitor of the upper capacitor group to adjust a variation. Lower bit AD conversion is now performed on the basis of the combined capacitance value of the selected capacitors. |
