ABSTRACT
One very important application of metal-oxide-semiconductor field-effect transistors (MOSFETs) (or MOSs) is in the arrangement known as a complementary metal oxide semiconductor (CMOS). CMOS is also known as “complementary symmetry metal oxide semiconductor.” The CMOS partly forms the mainstream of high-density digital system design technology, mostly used for fabricating very large-scale integrated (VLSI) or ultra-large-scale integrated (ULSI) chips because it is reliable, manufacturable, scalable, with low power and relatively low cost. CMOS is a type of MOSFET that uses complementary and symmetrical pairs of p-type and n-type MOSFETs (PMOS and NMOS transistors, respectively) to design and fabricate integrated circuits or chips to perform logic functions. MOSET concept has been discussed in Chapter 5. This chapter started by discussing the issue of noise, its sources and types, and how it affects the performance of CMOS. Afterwards, the constituents, configuration, fabrication, and design of CMOS into simple and complex logic circuits, as well as its formulation as transmission (or pass) gate and constitution into a VLSI chip are discussed. Also, the difference between static and dynamic CMOS transistors is discussed. In the construction of static CMOS gate, two complementary networks are used, where only one of which is enabled at any time. Whilst duality is sufficient for static correct operation, it is not necessarily so in reality. The noise margin of a digital circuit or gate is considered: an indication of how well the circuit or gate will perform under noisy conditions. Pass-transistor logic implements a logic gate as a simple switch network. The optimal pass-transistor stages of buffered chain and its delay are derived for minimization.
