CMOS image sensor for reducing kTC noise, reset transistor control circuit used in the image sensor and voltage switch circuit used in the control circuit

摘要

The present invention can be applied to a CMOS image sensor in which each pixel circuit of an active pixel sensor array includes a photoelectric conversion element for converting input light into electricity and a switch transistor for controlling the supply of a reset voltage for resetting the photoelectric conversion element to a predetermined voltage, to the photoelectric conversion element. The CMOS image sensor comprises a control circuit for assigning a control signal applied to a control electrode of the switch transistor. The control circuit outputs a first voltage much higher than a supply voltage of the CMOS image sensor so as to make an ON resistance of the switch transistor sufficiently small in the first part of a reset period of the photoelectric conversion element and outputs a second voltage lower than a supply voltage of the CMOS image sensor in the latter part of a reset period of the photoelectric conversion element.