On the low-frequency noise of DC-to-DC converters with random-switching control

The low-frequency output noise that is caused by introducing random-switching control into the DC-to-DC power converter is discussed quantitatively. A modified power converter model involving the unintended effect of random switching is derived from the consideration of noise-generation mechanisms. After a theoretical analysis based on the model, it is clarified that the magnitude of output noise is in proportion to the variance of switching interval. Experimental results from a buck-type power converter are compared with those obtained theoretically, so that the validity of the theoretical results is confirmed