Compared with an LDO device, a switching regulator always dissipates less heat and provides higher efficiency. Unfortunately, a switching regulator generates ripple and noise at both the output rail and the ground, and brings electromagnetic radiation. These interferences are almost inevitable due to the continuously on-off operation of the power switch. If the interference of the switching regulator can be effectively controlled, then the degrading of the system performance will be slight. This application note provides options to solve this issue.