ABSTRACT
This chapter describes how power is consumed in Complementary metal oxide semiconductor (CMOS) circuits. Power dissipation in a CMOS circuit consists of the following components: static, dynamic, and direct path power. Static power component is due to the leakage current drawn continuously from the power supply. The dynamic power component is dependent on the supply voltage, the load capacitances, and the frequency of operation. The chapter presents the probabilistic and statistical techniques to estimate power. Probabilistic technique has been used to solve the strong input pattern dependence problem in estimating the power consumption of CMOS circuits. The probabilistic technique, based on zero-delay symbolic simulation, offers a fast solution for calculating power. The probabilistic method in estimating power consumption uses signal probability measure to accurately estimate signal activity. The power consumption due to the internal nodes in the logic gates may play an important role in determining the total power consumption for a certain sequence of input vectors.
