Comparator and imaging device
AssigneeSony Semiconductor Solutions Corporation
InventorsMasayoshi Chiba, Shinichi Watanabe
Life of this patent
Estimating the term…
Abstract
The present technology relates to a comparator that can easily modify operating point potential of the comparator, and an imaging device. A pixel signal output from a pixel, and, a reference signal with changeable voltage are input to a differential pair. A current mirror connected to the differential pair, and a voltage drop mechanism allowed to cause a predetermined voltage drop is connected between a transistor that configures the differential pair, and a transistor that configures the current mirror. A switch is connected in parallel to the voltage drop mechanism. The present technology can be applied, for example, to an image sensor that captures an image.
Claims20
An imaging device comprising:
- a differential pair comprising:
- a first transistor configured to receive a pixel signal from a pixel circuit, and
- a second transistor configured to receive a reference signal from a reference signal output circuit;
- a current mirror electrically connected to a first power source;
- a first voltage drop transistor electrically connected between the current mirror and the first transistor;
- a second voltage drop transistor electrically connected between the current mirror and the second transistor;
- a first switch electrically connected in parallel to the first voltage drop transistor;
- a second switch electrically connected in parallel to the second voltage drop transistor;
- and
- a current source electrically connected to the differential pair, wherein
- the current source comprises a third transistor, a fourth transistor and a capacitor,
- the third transistor is electrically connected to the first transistor and the second transistor,
- the fourth transistor is electrically connected to the third transistor and a second power source which is lower voltage than the first power source, and
- the capacitor is electrically connected to a gate of the fourth transistor and the second power source.
An imaging system comprising:
- a lens;
- a pixel array connected to the lens;
- and
- converter circuitry, the converter circuitry comprising:
- a first transistor configured to receive a pixel signal from the pixel array,
- a second transistor configured to receive a reference signal from a reference signal output circuit,
- a current mirror electrically connected to a first power source,
- a first voltage drop transistor electrically connected between the current mirror and the first transistor,
- a second voltage drop transistor electrically connected between the current mirror and the second transistor,
- a first switch electrically connected in parallel to the first voltage drop transistor,
- a second switch electrically connected in parallel to the second voltage drop transistor, and
- a current source electrically connected to the differential pair, wherein
- the current source comprises a third transistor, a fourth transistor and a capacitor,
- the third transistor is electrically connected to the first transistor and the second transistor,
- the fourth transistor is electrically connected to the third transistor and a second power source which is lower voltage than the first power source, and
- the capacitor is electrically connected to a gate of the fourth transistor and the second power source.
Dependencies are inferred from the claim text.