Dual conversion gain gate and capacitor combination

A pixel cell comprising:

• a photosensor;
• a diffusion region for storing charge generated by the photosensor;
• and
• a dual conversion gain transistor coupled between the diffusion region and a capacitor, a gate of the dual conversion gain transistor forming one plate of the capacitor.

A pixel array comprising a plurality of pixel cells arranged in rows and columns, the pixel cells comprising:

• a photosensor;
• a diffusion region for storing charge generated by the photosensor;
• and
• a dual conversion gain transistor coupled between the diffusion region and a capacitor, a gate of the dual conversion gain transistor forming one plate of the capacitor.

A method of operating a pixel cell having a dual conversion gain transistor, the method comprising:

• resetting a diffusion region of the pixel cell to a pixel voltage supply level;
• sampling and holding a reset voltage level at the diffusion region;
• transferring charge accumulated in a photosensor of the pixel cell to the diffusion region;
• sampling and holding a pixel signal voltage level at the diffusion region;
• and
• activating the dual conversion gain transistor to connect a capacitor to the diffusion region after sampling and holding of the pixel signal voltage level.