The goal of Ultra-Low Voltage Nano-Scale Memories is to provide a detailed explanation of the state-of-the-art nanometer and sub-1-V memory LSIs that are playing decisive roles in power conscious systems. Emerging problems between the device, circuit, and system levels are systematically discussed in terms of reliable high-speed operations of memory cells and peripheral logic circuits. The effectiveness of solutions at device and circuit levels is also described at legnth.Voltage scaling is prevented by many resulting problems, such as the ever-decreasing signal-to-noise-ratio and voltage margin of many tiny flip-flop circuits in a memory-cell array and peripheral circuits, and the ever-increasing leakage and variation in speed caused by variations in process, voltage, and temperature. The problems and promising solutions at device and circuit levels are discussed in detail through clarifying noise compnents in an array, and even essential differences in ultra-low voltage operations between DRAMs and SRAMs. Moreover, various kinds of on-chip voltage converters necessary to solve the problems with internal power-supply managements are widely and deeply discussed.Ultra-Low Voltage Nano-Scale Memories, based on the authors' extensive experience in memory and low-voltage designs in industry, bridging the different necessary technologies between memory, digital, and analog technologies, and even between DRAMs and SRAMs. A lot of knowledge that authors have acquired to date, and circuits that authors regard as important are covered from the basics to the state-of-the-art. Thus, the book is beneficial to students and engineers interestedin ultra-low voltage nano-scale LSIs. Moreover, it is instructive not only for memory designers, but also for all digital and analog LSI designers who are the front edge of such LSI developments, since it is full of insight to develop such LSIs.
