Capacitor as a Resistor [Circuit Intuitions]

摘要

About 140 years ago, James Clerk Maxwell, who is well known today for his Maxwell equations, wrote A Treatise on Electricity and Magnetism (see Figure 1). In this book, he explained how a capacitor and a switch act effectively as a resistor. It was not known at the time that, 100 years later, this idea would form the essence of a class of ICs known as switched-capacitor circuits. This article reviews Maxwell's basic idea of how to implement a resistor using a capacitor and a switch and how to employ them in the design of a simple integrator.