High-speed CMOS image sensor circuits with in situ frame storage

Two CMOS image sensor circuit prototypes equipped with in situ frame storage have been fabricated and tested. Capable of 4-400 M-frames/s and between 66 and 79 dB rms dynamic range, these developments are intended for the capture of fast, brief, transient events with high resolution. Applications include accelerator-based flash radiography such as proton radiography. The first is a small two-dimensional (2-D) prototype in which each pixel includes either a capacitive trans-impedance amplifier or a direct-integration source-follower front end, followed by an array of 64 frame storage sample capacitors and associated readout electronics. The acquisition of either 32 frames using correlated double sampling (CDS) at 4 M-frames/s, or 64 frames without CDS at up to 10.5 M-frames/s (-3 dB), and up to 13 b dynamic range was achieved. The second is a monolithic solid state "streak camera", a 1-D linear array of 150 photodiodes, with a 150-frame analog storage array. This device reached 400-M-frames/s operation with electrical test inputs, at least 100-M-frames/s operation with optical inputs, and achieves over 11 b of dynamic range. These circuits demonstrate the high performance possible with CMOS sensor circuits containing in situ frame storage.