Signal generation circuit and photodetection apparatus

A photodetection apparatus comprising:

• a photodetection circuit that is configured to generate, by detecting light, a detection signal having a voltage dependent on an amount of received light;
• a signal generation circuit that is configured to generate a reference signal whose voltage varies with time;
• and
• a comparison circuit that is configured to perform a comparison operation on a basis of the detection signal and the reference signal, wherein
• the signal generation circuit includes
• a current source that is configured to flow a current from a first power supply node to a first node,
• a first capacitor that has one end coupled to the first node and another end coupled to a second node,
• an operation amplifier circuit that has a positive input terminal, a negative input terminal coupled to the second node, and an output terminal coupled to an output node,
• a first switch that has one end coupled to the second node and another end coupled to the output node,
• a second capacitor that has one end coupled to the first node and another end coupled to the output node,
• a first resistor that is provided in a first path that couples the first node and a second power supply node, and
• a second switch that is provided in the first path and is configured to turn on and off the first path.