Photoelectric conversion apparatus, imaging system, and method for driving photoelectric conversion apparatus

A photoelectric conversion apparatus comprising:

• a plurality of pixels each including a photoelectric conversion unit configured to generate a charge based on incident light, an amplification transistor having a node connected to the photoelectric conversion unit, and a selection transistor;
• a plurality of transistors having respective control nodes configured to receive a common potential;
• a switch;
• and
• a current source,
• wherein the amplification transistor, the selection transistor, the plurality of transistors, the switch, a power source voltage node, and the current source form a differential pair, and the differential pair has a first electric path and a second electric path between the power source voltage node and the current source,
• in the first electric path, the selection transistor is disposed between the current source and the amplification transistor, and
• in the second electric path, the switch is disposed between the current source and one of the plurality of transistors.

A method for driving a photoelectric conversion apparatus including a plurality of pixels each including a photoelectric conversion unit configured to generate a charge and an amplification transistor having a control node configured to receive the charge and to serve as a first input node of a differential pair, and a plurality of transistors having respective control nodes which receive a potential in common, wherein

• in a first operation,
• among the amplification transistors included in the plurality of pixels, at least one amplification transistor, that is, a first number of amplification transistors, is in an ON state for a first period, and
• among the plurality of transistors, at least one transistor, that is, a second number of transistors, is in an ON state for the first period and is set as a second input node of the differential pair, and
• in a second operation,
• among the amplification transistors included in the plurality of pixels, a number of amplification transistors corresponding to a number larger than the first number, that is, a third number of application transistors, are in ON states for a second period, and
• among the plurality of transistors, a number of transistors corresponding to a number larger than the second number, that is, a fourth number of transistors, are in ON states for the second period and are set as the second input node of the differential pair.

A photoelectric conversion apparatus comprising:

• a plurality of pixels each including a photoelectric conversion unit configured to generate a charge based on incident light and an amplification transistor having a control node configured to receive the charge and to serve as a first input node of a differential pair;
• a transistor having a control node serving as a second input node of the differential pair;
• a counter configured to generate and output a count signal obtained by counting a clock signal;
• and
• a memory configured to receive the count signal from the counter,
• wherein the amplification transistors of the plurality of pixels are brought into ON states, and
• digital signals corresponding to the charges of the plurality of pixels are generated in accordance with outputs of the differential pairs,
• wherein a ramp signal ramp is supplied to a control node of the transistor,
• the differential pair outputs, to the memory, a comparison result signal indicating a result of comparison between the ramp signal and signals output from the amplification transistors which are simultaneously in ON states and which are included in the plurality of pixels, and
• the memory stores the count signal when a value of the comparison result signal is changed.