{'fraction_non_alphanumeric': 0.028328611898016998, 'fraction_numerical': 0.021718602455146365, 'mean_word_length': 4.698924731182796, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Current-Mode ISFET Array with Row-Parallel ADCs for Ultra-High Speed Ion Imaging

This paper presents a fully integrated system-on-chip for ultra-high frame rate ion-imaging using a pH-sensing ISFET array. Linear pH-to-current conversion is achieved by operating the ISFET in velocity saturation which guarantees that the ion concentration in the chemical solution is linearly transduced to the output of the sensor. Implemented in a 3-Transistor (3-T) pixel for compactness, the ISFET also consists of a reset switch to compensate for sensor non-ideal effects such as trapped charge and drift. High speed readout is achieved using a current-mode signal processing pipeline while auto-zeroing is employed to reduce fixed pattern noise. The sensing array comprises 128 × 128 pixels and every row shares its own readout circuit followed by 128 row-parallel 1MS/sec single slope ADCs. Designed in standard TSMC 180nm CMOS process, the chip achieves 7800fps with 16k pixels and a silicon area of 2mm × 2mm, which is the fastest ISFET array reported in literature.