Power-Efficient CMOS Image Acquisition System based on Compressive Sampling
A novel compressive sampling scheme suitable for highly scalable hardware implementations is presented. The prototype design is implemented in a 0.18um standard CMOS technology and utilizes compressed acquisition to boost the overall power efficiency. Specialized pixels, convenient for Comparator-Based Switched Capacitor readout are developed for this purpose. A custom measurement matrix generation algorithm is implemented which reduces in-pixel hardware complexity and performs measurement matrix generation in a single clock cycle. Column-Parallel Differential Cyclic-ADCs based on the Zero-Crossing Detection (ZCD) technique are used to convert the analog image measurements. Physical IC design issues such as the device noise, mismatch and non-linearity, are analyzed and their effects on compressed image acquisition are discussed. The final simulation results show that the proposed 256x256 pixels architecture consumes 1.45mW at 250fps and 26.2mW at 8000fps. The architecture can easily be scaled towards newer technology nodes and higher image resolutions.