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 0.18μm 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 256×256 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.