Characterization and Redesign of a Modular 65-nm ASIC for Photon Counting with 20 e− Noise

Far-ultraviolet and extreme-ultraviolet (FUV/EUV) spectroscopic observations play a crucial role in multiple scientific domains, including solar physics and planetary exosphere studies. This work presents the first implementation of the Micro-channel plate Readout ASIC (MIRA), a 65-nm Application-Specific Integrated Circuit (ASIC) featuring a 32 × 32 pixel array of charge detectors for photon counting applications. We report both standalone performance measurements of MIRA and its characterization when coupled with a Micro-Channel Plate (MCP), demonstrating its feasibility for high-sensitivity detection in FUV/EUV applications. Furthermore, we describe the full-scale redesign of MIRA, transitioning from the initial 32 × 32 array to a more advanced 256 × 256 pixel architecture, featuring a larger detection area. This upgrade addresses critical design challenges, including supply voltage drops due to static current flow, analog front-end optimization for reduced power dissipation, and the implementation of a novel adaptive biasing stage to enhance performance.