Patent ID: 7858914

Claim:
A pixel cell coupled to a column readout circuit, the pixel cell comprising: a photosensor having a depletion region, a shallow trench isolation (STI) region proximate to the photosensor, a floating diffusion region coupled to the photosensor by way of a charge transfer transistor, an array pixel supply voltage configured to control a size of the depletion region, and a reset transistor connected between the floating diffusion region and the array pixel supply voltage, wherein the array pixel supply voltage includes first and second voltages, the array pixel supply voltage: 1) supplying the first voltage in a pixel to column readout period including a transfer of a charge from the photosensor to the floating diffusion region, and 2) supplying the second voltage in a column readout period including readout of the pixel cell by the column readout circuit, after a transfer of the charge from the floating diffusion region to the column readout circuit, and the depletion region has a first size such that the depletion region is spaced apart from the STI region with respect to the first voltage and the depletion region has a second size, responsive to the second voltage, such that the depletion region remains spaced apart from the STI region.