| 摘要 |
PROBLEM TO BE SOLVED: To correct a change component in the reference voltage of a digital/ analog(D/A) converting circuit and to simplify a circuit configuration by providing plural capacitor circuits between a D/A converter and a voltage comparator circuit and providing a level shift circuit for applying a voltage for compensating a voltage drop component caused by parasitic resistance to the plural capacitor circuits. SOLUTION: By adding an offset correcting capacitor Coff parallel with a sample/hold capacitor CSH and impressing different voltages to the capacitors between a sampling term and a comparate term, the correction ofΔV is added to a D/A converting voltage Vdac so that an analog input voltage VAIN coincides with the D/A converting voltage Vdac which corresponds to the theoretically obtained A/D converting code of VAIN. Thus, an offset error uniformly included in the entire D/A converting voltage from the most significant bit to least significant bit of a D/A converting code is relatively shifted just for +ΔV or -ΔV so that offset correction is enabled.
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