Patent ID: 8411184

Claim:
An image sensor comprising; a pixel array including a plurality of pixels arranged in rows and columns, wherein the pixels in each column are electrically connected to a column output line; a plurality of sample and hold circuits each electrically connected to a respective column output line, wherein each sample and hold circuit includes a first capacitor to receive a signal voltage and a second capacitor to receive a reset voltage, and further wherein each sample and hold circuit is electrically connected with the respective column output line and is electrically connected with a first local bus and a second local bus; a plurality of pairs of buffers with each pair of buffers electrically connected to a distinct group of two or more sample and hold circuits, wherein a first buffer of each of the plurality of pairs of buffers is electrically connected with the first local bus and is electrically connected with a first global bus, and further wherein a second buffer of each of the plurality of pairs of buffers is electrically connected with the second local bus and is electrically connected with a second global bus; wherein the first global bus to receive the signal voltages from at least a portion of buffers; wherein the second global bus to receive the reset signals from at least a portion of the other buffers; and further comprising at least one differential amplifier electrically connected to the first and second global buses to receive the signal voltage and the reset voltage and for determining a difference between the signal voltage and the reset voltage, wherein the first and second global buses each comprise two signal lines.