Analog-to-digital converter

An analog-digital conversion circuit for comparing a comparison potential with a reference potential generated based on a reference power supply to convert a comparison potential to a digital value, and outputting the digital value to an analog-to-digital converter, comprising

• the analog-to-digital converter that generates the comparison potential based on a potential that is sampled and held input potential, the digital value, and the reference power supply, the analog-to-digital converter comprising:
• bit circuits, each bit circuit corresponding to a bit of bits, the bit circuits comprising:
• a capacitor that receives the comparison potential from a first terminal, and capacitance value increases from low-order bit to high-order bit of the bits;
• a first switch to which the input potential is applied at a second terminal of the capacitor;
• a second switch that is electrically connected with the second terminal of the capacitor and the reference power supply;
• and
• a current amount control element;
• wherein the capacitor, the first switch, the second switch, and the current amount control element are connected in series;
• and
• a current amount control unit that controls current amount flowing to the current amount control element in each bit circuit of the bit circuits, wherein
• in response to second switches of the bit circuits being turned on in order from an upper bit in each bit circuit by the digital value, the current amount control unit applies a current control potential to the current amount control element in any of the bit circuits that a noise current is more than allowable value while the noise current proportional to a charge flowing from the capacitor to the reference power supply is more than the allowable value.