| 摘要 |
<p>Disclosed is a method and associated apparatus for compensating for kTC noise in individual pixels of an MOS imaging array. The kTC noise at issue forms when a pixel is disconnected from a reset voltage by turning off an MOS transistor which controls access to the pixel photodiode. Compensation is accomplished by first exposing the photodiode to the reset voltage and then disconnecting the well region from Vdd to cause it to float. By allowing the well to float, the kTC charge subsequently introduced (at the conclusion of the reset process) redistributes so that most of it accumulates on the capacitor between the well and the substrate. Later, the well is reclamped to Vdd, and the noise contribution stored in the well-substrate capacitor is canceled. A disclosed apparatus includes an array of pixels, each having a separate well. In addition, access of the well to a source of power (Vdd) must be switchable. Therefore, a transistor is included at each pixel's connection to a Vdd. <IMAGE></p> |
