Digital pixel readout integrated circuit for high dynamic range infrared imaging

Digital pixels enable the disassociation of well capacity with noise floor. This allows for better sensitivity for small signals and significantly increased well capacity for large signals. A 640 x 512 format, 20 μm pixel pitch digital pixel readout integrated circuit (DPROIC) for high dynamic range infrared imaging is presented. The architecture uses an extended counting approach that is optimized for low power consumption. This DPROIC boasts a programmable well capacity of 40 Me- in high gain (HG) and >400 Me- in low gain (LG) with no rollover. Read noise is 50 e- rms, HG, and 330 e- rms, LG, for integrate-then-read and 85 e- rms, HG, and 700 e- rms, LG, for integrate-while-read at 80 K. This readout, with LWIR SLS detectors, achieves single digit millikelvin noise-equivalent temperature difference.