Analog multiplexer configured to reduce kickback perturbation in image sensor readout

An analog multiplexing method comprising the steps of:

• receiving a plurality of input analog signal channels;
• and
• combining the plurality of input analog signal channels into a single output analog signal channel in an analog multiplexer comprising a plurality of input sampling circuits associated with respective ones of the input analog signal channels and an amplifier having an input controllably connectable in turn to each of the input sampling circuits;
• wherein in conjunction with the combining step at least a given one of the input analog signal channels is connected to a sampling element of its corresponding input sampling circuit at a predetermined time prior to connecting the sampling element of that input sampling circuit to the input of the amplifier;
• and
• wherein the predetermined time is less than a full clock cycle of a sampling clock of the amplifier.

An image sensor comprising:

• a pixel array;
• and
• readout circuitry coupled to the pixel array;
• the readout circuitry comprising an analog multiplexer configured to multiplex a plurality of input analog signal channels into a single output analog signal channel;
• the analog multiplexer comprising a plurality of input sampling circuits associated with respective ones of the input analog signal channels and an amplifier having an input controllably connectable in turn to each of the input sampling circuits,
• wherein the analog multiplexer is further configured to connect at least a given one of the input analog signal channels to a sampling element of its corresponding input sampling circuit at a predetermined time prior to connecting the sampling element of that input sampling circuit to the input of the amplifier;
• and
• wherein the predetermined time is less than a full clock cycle of a sampling clock of the amplifier.