Solid-state image sensor

Abstract

A solid-state image sensor comprising a pixel array having a plurality of pixels, and a plurality of signal processing circuits each of which amplifies a signal of the pixel array, wherein each of the plurality of signal processing circuits comprises an operation amplifier having an input terminal and an output terminal, an input capacitance arranged between the input terminal and the column signal line, and a feedback circuit which connects the input terminal with the output terminal, wherein the feedback circuit is configured to form a feedback path in which a first and a second capacitance elements are arranged in series in a path connecting the input terminal to the output terminal, and a third capacitance element is arranged between a reference potential and a path connecting the first capacitance element to the second capacitance element.

1 . A solid-state image sensor comprising a pixel array having a plurality of pixels, and a plurality of signal processing circuits each of said plurality of signal processing circuits amplifying a signal output from said pixel array to a plurality of column signal lines, wherein
 each of said plurality of signal processing circuits comprises   an operation amplifier which has an input terminal and an output terminal,   an input capacitance arranged between the input terminal and the column signal line, and   a feedback circuit which connects the input terminal with the output terminal, wherein   said feedback circuit is configured to form a feedback path in which a first capacitance element and a second capacitance element are arranged in series in a path connecting the input terminal to the output terminal, and a third capacitance element is arranged between a reference potential and a path connecting the first capacitance element to the second capacitance element.   
     
     
         2 . The solid-state image sensor according to  claim 1 , wherein
 said feedback circuit has an arrangement in which the first capacitance element and the second capacitance element are connected in series to connect the input terminal with the output terminal, and the third capacitance element is connected between a reference potential and a node connecting the first capacitance element to the second capacitance element.   
     
     
         3 . The solid-state image sensor according to  claim 1 , wherein
 the solid-state image sensor includes a first mode and a second mode as operation modes, and   said feedback circuit includes a plurality of switches, controlled to form the feedback path in the first mode and not to form the feedback path in the second mode.   
     
     
         4 . The solid-state image sensor according to  claim 1 , wherein
 said feedback circuit is configured to form the feedback path in response to a first control signal and to form, in response to a second control signal, a second feedback path connecting the input terminal to the output terminal via a capacitance element, and   an amplification factor of said signal processing circuit in forming the feedback path is different from that in forming the second feedback path.   
     
     
         5 . The solid-state image sensor according to  claim 1 , wherein
 each of said signal processing circuits includes   a first switch which connects the input terminal with one terminal of the first capacitance element,   a second switch which connects the output terminal with the other terminal of the first capacitance element,   a third switch which connects the input terminal with one terminal of the second capacitance element,   a fourth switch which connects the output terminal with the other terminal of the second capacitance element,   a fifth switch which connects the input terminal with one terminal of the third capacitance element,   a sixth switch which connects the output terminal with the other terminal of the third capacitance element,   a seventh switch which connects the other terminal of the first capacitance element with one terminal of the second capacitance element,   an eighth switch which connects the other terminal of the first capacitance element with the other terminal of the third capacitance element, and   a ninth switch which connects the one terminal of the third capacitance element with the reference potential.   
     
     
         6 . The solid-state image sensor according to  claim 5 , wherein
 the solid-state image sensor includes a first mode and a second mode as operation modes,   in the first mode, said first switch, said fourth switch, said seventh switch, said eighth switch, and said ninth switch are turned on, and   in the second mode, said second switch, said third switch, said fifth switch, and said sixth switch are turned on.   
     
     
         7 . The solid-state image sensor according to  claim 1 , wherein
 said operation amplifier is a fully-differential operation amplifier,   said feedback circuit forms the feedback path between an inverting input terminal and a non-inverting output terminal of said operation amplifier, and   each of said signal processing circuits further includes a second feedback circuit for forming a feedback path in which a fourth capacitance element and a fifth capacitance element are arranged in series between a non-inverting input terminal and an inverting output terminal of said operation amplifier in a path connecting the non-inverting input terminal to the inverting output terminal, and a sixth capacitance element is arranged between a reference potential and a path connecting the fourth capacitance element to the fifth capacitance element.   
     
     
         8 . The solid-state image sensor according to  claim 7 , wherein
 the reference potential is a common-mode potential of the fully-differential operation amplifier.   
     
     
         9 . A camera comprising:
 a solid-state image sensor according to  claim 1 ; and   a processing unit which processes a signal output from said solid-state image sensor.