Analog, Digital and Mixed-mode Signal Processing
The widespread use of digital signal processing systems is due to many factors including reliability, reproducibility, high precision, freedom from aging and temperature effects, low cost and efficient computational algorithms. Furthermore, the revolution in the microelectronics field [1–3] has been characterized by a continuous increase in the level of integration leading to complete systems being integrated on a single chip, that is, systems on a chip (SoC) [3–5].
The integrated circuit dates back to around 1960. Since then, the number of devices on a chip has increased dramatically in line with an observation [1, 2] predicting a doubling every year. Now, millions of transistors can be manufactured on a single chip allowing phenomenal processing capability. If we define a pixel as the smallest spot on a chip that can be controlled in the fabrication process, then this will determine the contribution of device miniaturization and chip area to the content of the chip. This contribution can be measured by the quantity A/S where A is the chip area and S is the pixel area. As progress continued, it was found that the number of devices on a chip was actually increasing faster than A/S. This additional growth was a result of “clever” techniques of exploiting the space on the chip. These include forming thin-film capacitors on the side holes etched into ...