Blooming free high dynamic range image sensor read out architecture using in-frame multi-bit exposure control

An imaging system, comprising:

• a pixel array having a plurality of pixel circuits arranged into a plurality of rows and a plurality of columns, wherein each one of the pixel circuits includes:
• a photodiode adapted to accumulate image charge in response to incident light;
• a transfer transistor coupled between the photodiode and a floating diffusion to selectively transfer the image charge accumulated in the photodiode to the floating diffusion;
• a selection circuit coupled to a control terminal of the transfer transistor to select one of a first transfer control signal, a second transfer control signal, or a third transfer control signal to control the transfer transistor,
• wherein the selection circuit is coupled to output the second transfer control signal in response to a precharge enable signal during a read out operation of a different row than a row in which the transfer transistor is included,
• wherein the selection circuit is coupled to output the second transfer control signal in response to a sample enable signal during a read out operation of the row in which the transfer transistor is included, and
• wherein the selection circuit is coupled to output the third transfer control signal to partially turn on the transfer transistor during an idle state of the pixel circuit including the photodiode;
• control circuitry coupled to the pixel array to control operation of the pixel array, wherein the selection circuit is included in the control circuitry;
• and
• read out circuitry disposed in the second semiconductor layer and coupled to the pixel array to read out image data from the plurality of pixel circuits.