Photoelectric conversion apparatus, imaging system, and moving object

A photoelectric conversion apparatus comprising:

• a photodiode to which a first voltage and a second voltage are supplied, the photodiode being an avalanche-multiplication-type photodiode;
• a counter configured to count a pulse generated at the photodiode, and hold a count value;
• a control circuit configured to control the first voltage to be supplied to the photodiode;
• and
• a correction unit configured to correct the count value output from the counter,
• wherein a signal input into the control circuit has a first level at which the first voltage is supplied to the photodiode via the control circuit and a second level at which the first voltage is not supplied to the photodiode, and
• wherein, in a case where the count value output from the counter exceeds a threshold value, the correction unit corrects a count value at which a gradient of the count value with respect to a number of photons incident on the photodiode in a range exceeding the threshold value falls in a range different from a gradient a of the count value with respect to a number of photons until the count value reaches the threshold value so as to match the gradient a.