Imaging device, semiconductor device and camera

An imaging device, comprising:

• a pixel circuit configured to generate an analog signal in accordance with a quantity of incident light;
• an amplification circuit configured to amplify the analog signal generated in the pixel circuit;
• a sample and hold circuit configured to perform sampling and holding of the analog signal amplified by the amplification circuit;
• a signal generation circuit configured to generate a reference signal that changes with time;
• an A/D conversion circuit configured to convert the analog signal held in the sample and hold circuit to a digital signal by using the reference signal;
• a determination circuit configured to generate a pulse for switching a time change rate of the reference signal used by the A/D conversion circuit in accordance with a result of a comparison between a threshold and a value of a signal output by the sample and hold circuit during a sampling period;
• and
• a buffer circuit connected between the sample and hold circuit and the A/D conversion circuit, wherein
• when the pulse is generated, the sample and hold circuit holds the analog signal after a rise and a fall of the pulse.

A semiconductor device for lamination comprising:

• an amplification circuit including a feedback capacitor and a switching element for resetting the feedback capacitor, the amplification circuit being configured to amplify an analog signal generated in response to a photoelectric conversion;
• a sample and hold circuit configured to perform sampling and holding of the analog signal amplified by the amplification circuit;
• an A/D conversion circuit configured to convert the analog signal held in the sample and hold circuit to a digital signal;
• a memory circuit configured to store the digital signal;
• a reading circuit configured to read the digital signal stored in the memory circuit;
• and
• a control circuit configured to generate a control signal for controlling on/off of the switching element, wherein
• the control circuit performs a rise and a fall of the control signal such that the rise and the fall do not overlap each of a conversion period of the analog signal by the A/D conversion circuit and a reading period of the digital signal by the reading circuit when the switching element is off during a sampling period of the analog signal.

A semiconductor device for lamination comprising:

• an amplification circuit configured to amplify an analog signal generated in response to a photoelectric conversion;
• a sample and hold circuit configured to perform sampling and holding of the analog signal amplified by the amplification circuit;
• a signal generation circuit configured to generate a reference signal that changes with time;
• an A/D conversion circuit configured to convert the analog signal held in the sample and hold circuit to a digital signal by using the reference signal;
• a determination circuit configured to generate a pulse for switching a time change rate of the reference signal used by the A/D conversion circuit in accordance with a result of a comparison between a threshold and a value of a signal output by the sample and hold circuit during a sampling period;
• and
• a buffer circuit connected between the sample and hold circuit and the A/D conversion circuit, wherein
• when the pulse is generated, the sample and hold circuit holds the analog signal after rise and fall of the pulse.