AD converter, AD converter, photoelectric converter, imaging system, and AD conversion method

摘要

PROBLEM TO BE SOLVED: There is a concern that the dynamic range with respect to the amount of incident light becomes insufficient and the power consumption becomes large. SOLUTION: When a magnitude of an analog signal falls below a threshold, a p-bit digital signal is obtained by comparing the analog signal with a first reference signal in the comparator, and the magnitude of the analog signal is If the threshold is exceeded, the comparator compares the analog signal with a second reference signal that has a greater rate of change over time than the first reference signal to obtain a q-bit digital signal less than p bits. [Selected figure] Figure 5