Event-driven ROICs optimized for high sensitivity and event throughput at MWIR

This work presents advances in readout integrated circuit (ROIC) design for event-based infrared (IR) imagers, focusing on pixel- and array-level innovations that enhance sensitivity, throughput, power efficiency, and uniformity. Two generations of 32×32-pixel arrays are demonstrated. The first integrates a classical logarithmic pixel (LOG-NCG) and a new linear-response pixel (LIN-TIA) optimized for high-background operation, achieving >90 dB dynamic range, <1.8 K minimum event temperature (MET), and <10 µs latency. The LIN-TIA enables tunable contrast sensitivity down to 1.82% (~500 mK MET) with stable background response. Simulation results for the second-generation array, which incorporates a photovoltaic change-detector (PVCD) pixel, show MET below 300 mK while reducing pixel power to ~50 µW. New change-detector amplification and non-uniformity correction schemes improve contrast threshold uniformity (CTNU) and sensitivity. Implemented in 0.18 µm CMOS with 30 µm pitch, these architectures provide a scalable, low-power foundation for next-generation event-based IR imaging systems.