Photoelectric conversion device, photoelectric conversion system, movable object and equipment
The photoelectric conversion device includes a plurality of pixels each including a photoelectric conversion unit and an amplification unit configured to amplifies a signal based on charge generated by the photoelectric conversion unit, an output line connected to the plurality of pixels, an interconnection disposed adjacent to the output line, and a current source circuit connected to the output line and configured to supply a current to the amplification unit of the pixel via the output line. The current source circuit includes a current source transistor connected between the interconnection and a fixed voltage node, and a cascode transistor connected between the interconnection and the output line.
1 . A photoelectric conversion device comprising:
a plurality of pixels arranged to form a column and each including a photoelectric conversion unit and an amplification unit configured to amplify a signal based on charge generated by the photoelectric conversion unit;
an output line connected to the plurality of pixels;
an interconnection disposed adjacent to the output line; and
a current source circuit connected to the output line and configured to supply a current to the amplification unit of the pixel via the output line,
wherein the current source circuit includes a current source transistor connected between the interconnection and a fixed voltage node, and a cascode transistor connected between the interconnection and the output line.
2 . The photoelectric conversion device according to claim 1 , wherein a transconductance of the cascode transistor is greater than a transconductance of the current source transistor.
3 . The photoelectric conversion device according to claim 1 , further comprising: a transistor connected between the current source transistor and the output line and having a conductivity type opposite to that of the current source transistor.
4 . The photoelectric conversion device according to claim 1 , further comprising:
a first substrate provided with the plurality of pixels; and
a second substrate stacked over the first substrate and provided with the current source circuit.
5 . The photoelectric conversion device according to claim 4 ,
wherein the output line is divided into
a first portion disposed on the first substrate and to which a part of the plurality of pixels is connected,
a second portion disposed on the first substrate and to which another part of the plurality of pixels is connected, and
a third portion disposed on the second substrate and connected to the current source circuit, and
wherein the photoelectric conversion device further comprises a first selection circuit disposed on the second substrate and configured to select one of the first portion and the second portion of the output line and electrically connect the selected one to the third portion of the output line.
6 . The photoelectric conversion device according to claim 5 ,
wherein the interconnection is divided into
a first portion disposed on the first substrate adjacent to the first portion of the interconnection,
a second portion disposed on the first substrate adjacent to the second portion of the interconnection, and
a third portion disposed on the second substrate adjacent to the third portion of the interconnection and connected to the current source circuit, and
wherein the photoelectric conversion device further comprises a second selection circuit disposed on the second substrate and configured to select one of the first portion and the second portion of the interconnection and electrically connect the selected one to the third portion of the interconnection.
7 . The photoelectric conversion device according to claim 4 ,
wherein the output line is divided into
a first portion disposed on the first substrate and to which a part of the plurality of pixels is connected,
a second portion disposed on the first substrate and to which another part of the plurality of pixels is connected,
a third portion disposed on the second substrate and electrically connected to the first portion, and
a fourth portion disposed on the second substrate and electrically connected to the second portion, and
wherein the current source circuit includes
a first current source circuit electrically connected to the third portion, and
a second current source circuit electrically connected to the fourth portion.
8 . The photoelectric conversion device according to claim 1 ,
wherein the output line comprises a plurality of output lines provided corresponding to the column and each connected to at least one of the plurality of pixels,
wherein the interconnection comprises a plurality of interconnections provided corresponding to the column and each arranged adjacent to any one of the plurality of output lines in parallel,
wherein the current source circuit comprises a plurality of current source circuits provided corresponding to the plurality of output lines and each configured to supply a current to the amplification unit of the pixel connected to the corresponding output line, and
wherein each of the plurality of interconnections is connected to the current source circuit connected to the output line arranged adjacent thereto.
9 . The photoelectric conversion device according to claim 8 , wherein the plurality of output lines is arranged between two of the plurality of interconnections in a plan view.
10 . The photoelectric conversion device according to claim 8 , wherein the plurality of output lines is adjacent to each other without interposing another interconnection.
11 . The photoelectric conversion device according to claim 8 , wherein the number of output lines is greater than the number of the interconnections.
12 . The photoelectric conversion device according to claim 8 , wherein each of the plurality of output lines is sandwiched by the two interconnections connected to the same current source circuit.
13 . The photoelectric conversion device according to claim 8 , wherein at least two of the plurality of output lines are comprised of an interconnection layer of the same level.
14 . The photoelectric conversion device according to claim 8 , wherein at least two of the plurality of output lines are comprised of interconnection layers of different levels.
15 . The photoelectric conversion device according to claim 8 , wherein at least one of the plurality of output lines and the plurality of interconnections is comprised of a plurality of interconnection layers of different levels.
16 . The photoelectric conversion device according to claim 15 , wherein each of the plurality of interconnections is comprised of interconnection layers of the number greater than the number of interconnection layers comprising each of the plurality of output lines.
17 . The photoelectric conversion device according to claim 16 , wherein at least a part of the interconnection layers comprising the plurality of interconnection overlaps at least one of the plurality of output lines in a plan view.
18 . The photoelectric conversion device according to claim 8 ,
wherein the plurality of output lines includes a first output line and a second output line,
wherein the plurality of interconnections includes a first interconnection and a second interconnection,
wherein the plurality of current source circuit includes
a first current source circuit, a second current source circuit, and a switch circuit configured to switch between a first mode in which the first current source circuit is connected to the first output line and the first interconnection and the second current source circuit is connected to the second output line and the second interconnection, and a second mode in which the first current source circuit is connected to the first output line and the first interconnection and the second interconnection is connected to the first interconnection.
19 . The photoelectric conversion device according to claim 1 , wherein the current source circuit further includes a negative capacitance circuit connected to the output line.
20 . The photoelectric conversion device according to claim 1 , wherein the output line and the interconnection are arranged adjacent to each other in a pixel array unit in which the plurality of pixels is arranged.
21 . The photoelectric conversion device according to claim 1 , further comprising a pixel array unit in which a plurality of the columns is arranged.
22 . The photoelectric conversion device according to claim 1 , wherein the amplification unit is configured by a source follower circuit.
23 . The photoelectric conversion device according to claim 1 , wherein the amplification unit is configured by a common-source amplifier circuit.
24 . The photoelectric conversion device according to claim 1 , wherein the amplification unit is configured by a differential amplifier circuit.
25 . A photoelectric conversion system comprising:
the photoelectric conversion device according to claim 1 ; and
a signal processing device configured to process a signal output from the photoelectric conversion device.
26 . A movable object comprising:
the photoelectric conversion device according to claim 1 ; and
a distance information acquisition unit configured to acquire distance information to an object from a parallax image based on a signal from the photoelectric conversion device; and
a control unit configured to control the movable object based on the distance information.
27 . Equipment comprising:
the photoelectric conversion device according to claim 1 , and
at least one of
an optical device corresponding to the photoelectric conversion device,
a control device configured to control the photoelectric conversion device,
a processing device configured to process a signal output from the photoelectric conversion device,
a mechanical device that is controlled based on information obtained by the photoelectric conversion device,
a display device configured to display information obtained by the photoelectric conversion device, and
a storage device configured to store information obtained by the photoelectric conversion device.
28 . A photoelectric conversion device comprising:
a plurality of pixels arranged to form a column and each including a photoelectric conversion unit and an amplification unit configured to amplify a signal based on charge generated by the photoelectric conversion unit;
an output line connected to the plurality of pixels;
an interconnection disposed adjacent to the output line; and
a current source circuit connected to the output line and configured to supply a current to the amplification unit of the pixel via the output line,
wherein the current source circuit includes a current source transistor connected between the output line and the interconnection, and a resistor connected between the interconnection and a fixed voltage node.
29 . A photoelectric conversion device comprising:
a plurality of pixels arranged to form a column and each including a photoelectric conversion unit and an amplification unit configured to amplify a signal based on charge generated by the photoelectric conversion unit;
an output line connected to the plurality of pixels;
a current source circuit connected to the output line and configured to supply a current to the amplification unit of the pixel via the output line;
a first substrate provided with the plurality of pixels; and
a second substrate stacked over the first substrate and provided with the current source circuit,
wherein the output line is divided into
a first portion disposed on the first substrate and to which a part of the plurality of pixels is connected,
a second portion disposed on the first substrate and to which another part of the plurality of pixels is connected, and
a third portion disposed on the second substrate and connected to the current source circuit,
wherein the photoelectric conversion device further comprises a selection circuit disposed on the second substrate and configured to select one of the first portion and the second portion and electrically connect the selected one to the third portion, and
wherein the current source circuit includes a current source transistor connected to the output line and a negative capacitance circuit connected to the output line.
30 . The photoelectric conversion device according to claim 29 , further comprising a third substrate stacked over the first substrate and the second substrate and provided with an analog-to-digital conversion circuit configured to perform analog-to-digital conversion on a signal output from the output line.