ANALOG-TO-DIGITAL CONVERTER AND IMAGE SENSOR

摘要

An analog-to-digital converter has a comparator to compare, within a predetermined period, an input signal with a ramp signal or with a triangle wave signal, a first counter to count up or down in accordance with a logic of a signal that indicates a comparison result of the comparator within the predetermined period, a count value storage to sequentially store count values of the first counter whenever the logic of the signal that indicates a comparison result of the comparator changes within the predetermined period, a second counter to count the number of times the logic of the signal that indicates a comparison result of the comparator changes, and an arithmetic module to output a value obtained by adding up the count values stored in the count value storage and dividing the added-up value by a count value of the second counter.

主权项

1. An analog-to-digital converter comprising:
a comparator to compare, within a predetermined period, an input signal with a ramp signal whose signal level monotonically increases or monotonically decreases with time, or with a triangle wave signal that alternately repeats monotonic increase and monotonic decrease with time; a first counter to count up or down in accordance with a logic of a signal that indicates a comparison result of the comparator within the predetermined period; a count value storage to sequentially store count values of the first counter whenever the logic of the signal that indicates a comparison result of the comparator changes within the predetermined period; a second counter to count the number of times the logic of the signal that indicates a comparison result of the comparator changes; and an arithmetic module to output a value obtained by adding up the count values stored in the count value storage and dividing the added-up value by a count value of the second counter, as an analog-to-digital conversion value of the input signal.