摘要 |
A method of scanning pixels, each pixel including a photodiode and a sense node formed in the substrate, including a transfer gate coupled between the photodiode and the sense node, and including a memory gate coupled between the photodiode and the transfer gate. The method switches a control signal, connected to a memory gate electrode of all pixels, alternately between a first voltage and a second voltage that is intermediate between the first voltage and a substrate voltage. The first voltage transfers all photo charge in each photodiode into the respective memory gate. The second voltage both (1) holds all photo charge already transferred into the memory gate and (2) blocks further transfer of photo charges into each memory gate. The method further includes reading out photo charge from the memory gate on a row-by-row basis while the control signal is at the second voltage. |