Memories have played a vital role in embedded system architectures over the years. A need for high-speed memory to be embedded with state-of-the-art embedded system to improve its performance is essential. This chapter focuses on the development of high-speed memories. The traditional static random access memory (SRAM) is first analyzed with its different variant in terms of static noise margin (SNM); these cells occupy a larger area as compared to dynamic random access memory (DRAM) cell, and hence, a comprehensive analysis of DRAM cell is then carried out in terms of power consumption, read and write access time, and retention time. A faster new design of P-3T1D DRAM cell is proposed which has about 50% faster reading time as compared to the traditional three-transistor DRAM cell. A complete layout of the structure is drawn along with its implementation in a practical 16-bit memory subsystem.
Part of the book: Advanced Electronic Circuits
Piezoelectric energy harvesting is a way of converting waste mechanical energy into usable electrical form. The selection of mechanical devices for conversion of mechanical to electrical energy is a significant part of vibration energy harvesting. The articles provide designing and optimization of a cantilever piezoelectric energy harvester. At first, is the selection of best mechanical device for energy harvesting application. A cantilever without proof mass is then analyzed for the selection of substrate, and piezoelectric material also plays a key role in the performance of the device. Aluminum is selected as a substrate, while zinc oxide acts as the piezoelectric layer. Addition of proof mass reduces the resonant frequency of the device to about 51 Hz as compared to 900 Hz for an aluminum cantilever beam. An electromechanical study shows an active conversion of mechanical input energy to electrical output energy. Power frequency response functions of the resultant structure are able to generate 0.47 mW power having 6.8 μA current at 1 g input acceleration.
Part of the book: Nanogenerators