Multi-mode high capacity dual integration direct injection detector input circuit

An array of unit cells, each said unit cell comprising an input node for coupling to an output of a detector of electromagnetic radiation;

• a first capacitor switchably coupled to said input node for receiving a charge signal from said detector and for integrating said charge signal during a high gain integration period;
• a second capacitor switchably coupled to said input node for receiving a charge signal from said detector and for integrating said charge signal during a lower gain integration period;
• and an output circuit for coupling said first capacitor to a first output signal line during a charge signal readout period, and for coupling said second capacitor to a second output signal line during said charge signal readout period, said array further comprising a first amplifier having an input coupled to said first output signal line, a second amplifier having an input coupled to said second output signal line, a comparator for comparing an output of said first amplifier to a saturation threshold signal, and an output multiplexer, coupled to an output of said comparator, for selecting one of the output of said first amplifier or an output of said second amplifier to be coupled to further circuitry.