The switching power supply manufacturer tells you how the ripple is generated?
If you don't know, you can just follow the editor to understand how the ripple of the switching power supply manufacturer is generated. In fact, it is to reduce the output ripple to an acceptable level. If there is more than this, then reduce the ripple, but we need to know the type and cause of the ripple of the switching power supply manufacturer.
With the switching of the SWITCH, the current in the inductor L actually floats up and down the effective value of the output current. Therefore, a ripple of the same frequency will also appear at the output end. Generally speaking, this is the ripple. It is related to the volume and ESR of the output capacitor. The frequency of this ripple is the same as that of the switching power supply manufacturer.
Another is that the bipolar rotator or MOSFET is generally used, but no matter what it is, there will be a rise time and a fall time when it is turned on and off. In the power supply circuit, there will be a frequency of the same rise and fall time as before, or the noise of an odd number of optical lenses is usually tens of MHz. The same diode D has a reverse recovery moment, and its equivalent circuit is the series connection of electronic components and inductors, which will cause resonance, and the resulting noise frequency is also several tens of MHz. These two types of noise are often referred to as high frequency noise, and the magnitude is generally much larger than the ripple.
If it is an AC/DC converter, in addition to the above two kinds of ripple noise, there is also AC noise. The frequency is the frequency of the manufacturer of the AC switching power supply, which is around 50 to 60 Hz. There is also this common mode noise, which is caused by the equivalent capacitor caused by the application of the chassis as a heat pipe radiator in the power electronic devices of many switching power supply manufacturers.