Automatic integration and readout gain read out integrated circuit (ROIC)

A method for imaging having both integration time gain and readout gain comprising:

• receiving, at a plurality of pixels, photons from an image;
• providing a first, short, integration time output and a second, long, integration time output from each pixel of said plurality of pixels;
• receiving said short integration time output and said long integration time output at a gain selection component of a column cell of a Read Out Integrated Circuit (ROIC);
• comparing, in said gain selection component of said column cell, said pixel long integration time output and a gain to at least one threshold;
• determining a data bit output and a gain bit output from said comparison;
• whereby a dynamic range of said imaging method is extended;
• wherein said method comprises three phases comprising:
• a first phase comprising selection of said readout gain;
• a second phase comprising selection of said integration time gain;
• and
• a third phase comprising final settling before sample and hold.

A system for imaging having both integration time gain and readout gain comprising:

• a plurality of pixels comprising a frame, each said pixel comprising:
• a direct injection input with two Sample-and-Holds (SHs);
• a short integration time output;
• and
• a long integration time output, whereby said integration time gain extends a range to higher fluxes with shorter integration times;
• a Read Out Integrated Circuit (ROIC) comprising:
• at least one column cell comprising:
• a gain selection component wherein each of said short integration time output and said long integration time output are compared to a threshold producing gain bits;
• and
• an Analog to Digital Converter (ADC) producing data bits;
• wherein a first phase readout gain selection comprises:
• establishing said readout gain in a high gain configuration;
• comparing a value of said long integration time output to a readout gain threshold;
• if said long integration time output value is greater than said readout gain threshold, then switching said high readout gain to a low readout gain configuration;
• wherein a second phase integration time gain selection comprises:
• comparing a value of said long integration time output multiplied by a readout gain to an integration time gain threshold;
• if said long integration time output value multiplied by said readout gain is greater than said integration time gain threshold, then switching to said short integration time output;
• wherein a third phase final settling comprises:
• maintaining a readout gain and an integration time gain;
• connecting to a capacitor of said sample-and-hold for final setting;
• outputting said gain bits;
• and
• outputting said data bits;
• wherein said column cell outputs said data bits from said ADC and said gain bits for each said pixel;
• whereby a dynamic range of said imaging device is extended.