Abstract： This article outlines power， ground， PCB， and system layout hints and kinks. It includes an overview of using power， ground star points， and multifrequency power decoupling. It also shows how to control the component placement to minimize the size of the high-current switching loop.

　　Just like a high-rise building in earthquake-prone areas， great circuit design depends on a good foundation for its longevity and usefulness.

　　Perfect electronics power supply transforms the alternating current （AC） distributed to our homes and factories into direct current （DC） that electronics need. In a perfect world， the direct current would be noise-free or free of ripple or harmonics from the AC. In addition， the ground， which is the reference for our DC power， would be clean and pristine. As engineers， we quickly learn our world is far from perfect. That means we have to use our skill and knowledge to obtain the desired results despite the limitations.

　　One must first understand the operating environment and realize there is often radio frequency interference from external transmitters as well as the digital circuits operating on the same printed circuit board （PCB）。 Let’s start by examining the AC plug. In most cases， a powerline filter such as the one depicted in Figure 1 is desirable.