Lock Down That Noise - Don't Let It Escape

摘要

How can I prevent switching-mode power supply noise from devastating my circuit performance?rnWith great difficulty - but it can be done.rnSwitching-mode power supplies are inherently the noisiest circuits imaginable. A large current from the supply is being turned on and off at high frequency with very fast dl/dt. There are inevitably large fast voltage and current transients.rnThe only way to prevent interference to sensitive circuitry in the system is to keep the transients within the converter. We cannot stop switching large currents inside it, but we can, and must, prevent the transient currents and voltages from escaping. Start by grounding all the terminals of the converter at AC.