摘要 |
One embodiment of the present invention describes a pixel circuit that comprises at least one photodiode, a first transistor coupled between the photodiode and a floating diffusion node, a second transistor coupled between the floating diffusion node and a modifiable driving voltage signal, and a third transistor having a gate coupled to the floating diffusion node, a source coupled to a signal output, and a drain coupled to a constant voltage. Another embodiment of the present invention provides a method for driving the pixel circuit, which comprises resetting the photodiode and the floating diffusion node, exposing the photodiode to light to accumulate charges, selecting the pixel circuit by switching the driving voltage signal from a first voltage level to a second voltage level, retrieving a reference voltage from the selected pixel circuit, and retrieving an image signal from the selected pixel circuit corresponding to the accumulated charges.
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