OrthoPix: A novel compressing architecture for pixel detectors

We describe here a new architecture, dubbed OrthoPix, designed to compress data arrays where only a few elements carry relevant information. Pixel detectors used for particle tracking in High Energy Physics, Medical Imaging and other disciplines are the intended target of such a development. In these and similar applications the relevant number of pixel hit per frame (occupancy) is small (on the order or less than 1%), therefore data compression is mandatory to save bandwidth and reach frame rates in excess of millions per second. Current state of the art employs complex circuitry into the pixel cell to discriminate relevant signals, leading to an extremely effective, non-destructive compression at the price of large power consumption and pixel area limitations. Orthopix instead implements a passive projective compression, leading to low power, small pixel cell and large area devices. Power saving and pixel compactness come from the fact the projective compression is lossy, thereby data reconstruction efficiency degrades for higher occupancies.