CMOS image sensor and method for operating a CMOS image sensor in a weak inversion mode with increased dynamic range

摘要

There is disclosed a CMOS technology image sensor and a method for operating such an image sensor. This sensor includes a plurality of pixels (50) each including a photo-sensor element (PD) producing charge carriers in proportion to its illumination and storage means (C1) capable of being coupled and uncoupled from the photo-sensor element at a determined instant in order to store, on a memory node (B) of the pixel, a measuring signal representative of the charge carriers produced by said photo-sensor element during an exposure phase.;Each pixel includes at least one MOS transistor (M1; M3) connected in series via its drain or source terminals to the photo-sensor element, and the transistor is configured such that it operates at least partially in weak inversion so that, during the exposure phase, the pixel has a logarithmic response for illumination levels higher than a determined illumination level.;This at least partially logarithmic response enables the pixel dynamic range to be increased.