REFERENCE VOLTAGE GENERATION CIRCUIT, A/D CONVERTER AND SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To improve the accuracy of an A/D converter. SOLUTION: The reference voltage generation circuit is provided with capacitors C1 to Cn connected to the reference voltage supply terminals of respective comparators 13-1 to 13-n, constant current sources 12-1 to 12-n for charging the capacitors C1 to Cn and switching circuits 11-1 to 11-n for intermittently supplying constant currents to the capacitors C1 to Cn. From the viewpoint of variation in manufacturing, the properties of the capacitors C1 to Cn and the constant current sources 12-1 to 12-n are deviated from the design values similarly to that of other elements in the A/D converter. Consequently, the accuracy of A/D conversion can be improved by offsetting the manufacturing variation of elements in the comparators 13-1 to 13-n.