I have been learning some knowledge about switching circuits in the past two days. I have always been curious about a problem in the buck circuit. When the switch is turned off, the inductance will generate a very high back-EMF, but I read many books and online explanations and did not give Give an explanation about the back-EMF, where did you solve this back-EMF? Is it because the frequency of the generated back EMF is so high that it is filtered out by the LC low-pass filter?
Nolan Posted on November 12, 2020
The buck topology does not first switch to charge the inductor and then disconnect the power switch to allow the inductor to supply power through the induced potential, so as to achieve a step-down, so the induced voltage you said was originally used to generate the load voltage, and the capacitor The characteristic is that the voltage will not change suddenly, and the output voltage can be smoothed through the capacitor. Of course, you can also use the idea of low-pass filtering.
Melanie Posted on November 12, 2020
Reverse diode freewheeling.
Brody Posted on November 12, 2020
On the one hand, there is a freewheeling diode to charge the capacitor, and on the other hand to provide current to the load.
