Skip to main content
main-content

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
CMOS (Complementary Metal Oxide Semiconductor) is the most interesting technology presently available for mass production of chips, because of its low power dissipation, good scalability and speed. After a slow start, due to difficulties in the fabrication process, CMOS became a mature technology in the early eighties and will be more and more widely used as time goes by. One of the fascinating features of CMOS is its very wide range of applications: CMOS circuits can be found both in wrist-watches and supercomputers, covering the entire range of the electronic market. The future of CMOS looks even brighter.
Marco Annaratone

Chapter 2. MOS Transistor Characteristics

Abstract
The literature on MOS transistor characteristics is extensive. The purpose of this chapter is to review the fundamentals of MOS technology through the use of simplified models. A more accurate model to compute the voltage transfer function of an inverter will be introduced in Section 2.6. Most of the equations presented in this chapter will not be justified. The reader interested in a more comprehensive treatment of MOS physics should refer to references at the end of the chapter [34,22,35,25,21].
Marco Annaratone

Chapter 3. Fabrication Processes

Abstract
CMOS processes are generally more complex and expensive than nMOS processes because extra steps and extra masks are required in the fabrication process. Although many different processes are available, all the CMOS processes fall into either one of the two following classes:
  • Bulk processes: the substrate is doped silicon. Examples of bulk processes are p-well, n-well, and twin-tub. Newer bulk processes [18,32] can also have bipolar transistors on the same wafer, which has positive effects on driving capability — which is not as high in MOS as in bipolar technology — and when digital/analog applications — such as sense amplifiers in memory design [17] — are considered.
  • Silicon-on-insulator (SOI) processes: the substrate is an insulator, such as sapphire (“silicon-on-sapphire,” SOS) or silicon dioxide (SiO2).
Marco Annaratone

Chapter 4. Logic Design

Abstract
Several logic design techniques can be used in CMOS; however, all of them belong to one of the following logic disciplines:
  • Static logic.
  • Dynamic logic.
  • Bootstrap logic.
Marco Annaratone

Chapter 5. Circuit Design

Abstract
Circuit design requires a global optimization of various parameters, given the specifications of the chip. The most important parameters that the designer has to consider are speed, area, noise margin, and power dissipation. The last parameter is somewhat less important than the others in CMOS technology, but with the frequency of circuit operation steadily increasing this no longer holds true. Moreover, as we shall see in Chapter 7, power dissipation considerations become extremely important when we consider the input/output section of the chip.
Marco Annaratone

Chapter 6. Design of Basic Circuits

Abstract
The aim of this chapter is not to present a complete, in-depth analysis of every possible building-block that can be found in today’s VLSI circuits. Rather, a limited number of circuits is dealt with. This chapter presents circuits of increasing complexity: it starts with flip-flops and latches and ends with multipliers. More complex circuits — such as floating-point or memory management units — have not been considered, because an in-depth treatment — including architectural issues, logic design methodologies, and actual implementation — would have eventually occupied a large portion of the book.
Marco Annaratone

Chapter 7. Driver and I/O Buffer Design

Abstract
CMOS I/O buffers and bus drivers — or any circuit which is to drive a significant load both on-chip and off-chip — have not received much attention in the literature, and a comprehensive treatment of them — delay minimization, power dissipation, second order effects, and layout techniques to minimize noise and maximize speed — is lacking. This chapter aims at filling this gap: both input and output buffers will be dealt with, from the stand-point of speed, power dissipation, noise robustness, degree of protection, etc. The design of on-chip drivers — such as bus drivers — can differ from the design of output buffers, because both transmitting and receiving stages are under the designer’s control, and, therefore, a global optimization can be effectively carried out. Nonetheless, simple and reliable approaches are still implemented — for instance, scaled-up inverter chain. In this respect the design of on-chip drivers can be treated like the design of output buffers. Finally, on-chip driver design which optimize both transmitter and receiver is presented in Section 7.8.
Marco Annaratone

Backmatter

Weitere Informationen