Radiation imaging apparatus and radiation imaging system

An apparatus comprising:

• a sensor array in which a plurality of sensors each configured to detect radiation is arranged;
• a readout circuit configured to read out a signal from the plurality of sensors;
• an output circuit configured to output the signal;
• a driving unit configured to drive the plurality of sensors;
• a controller configured to perform first control for resetting the plurality of sensors by causing the driving unit to drive the plurality of sensors before start of radiation irradiation, second control for causing the driving unit to accumulate charges in the plurality of sensors after the start of the radiation irradiation, and third control for causing the driving unit to drive the plurality of sensors to cause the output circuit to output the signal after the second control;
• and
• a power supply circuit including a first switching voltage regulator that generates a voltage for the readout circuit and a second switching voltage regulator that generates a voltage for the output circuit,
• wherein the second voltage regulator generates the voltage for the output circuit based on a first clock signal provided from the controller in the third control, and generates the voltage for the output circuit based on a second clock signal in the first control, the second clock signal being lower in power consumption of the second voltage regulator than the first clock signal, and
• wherein the first voltage regulator generates the voltage for the readout circuit based on a third clock signal provided from the controller in the first control, the second control, and the third control.