Measuring High-Frequency Noise in Buck-Regulator Output-Voltage Ripple (Download)
In many applications, a switch-mode power supply (SMPS) is the only choice because of its excellent performance, including high efficiency and high power capability. A buck step-down power converter is the most popular topology adopted in a variety of applications. The switching characteristics controlled by pulse-width modulation (PWM) help to regulate power transfer.
At the same time, though, the fast switching transients of power FETs within several nanoseconds or tens of nanoseconds could induce high-frequency noises. For example, in noise-sensitive applications, if the high-frequency voltage spikes caused by the power supply are aligned with the clock signal, it will cause failure or malfunction of the load devices, such as ADCs, ASICs, or FPGAs.
