摘要 |
According to one embodiment, an A/D converter includes a determination circuit configured to determine whether a first analog signal is greater than a second analog signal or not, the first analog signal being a present A/D conversion target, the second analog signal being an immediately preceding A/D conversion target, a calculation circuit configured to add a reference voltage to a difference obtained by subtracting the second analog signal from the first analog signal, a generation circuit configured to generate a comparison voltage, a comparator configured to compare a calculated value of the calculation circuit with the comparison voltage, and a conversion circuit configured to convert a period into a digital signal, the period being required until the calculated value is identical with the comparison voltage by the comparator. |