Digital control of power converters has been an\udarea of considerable research interest in recent times. One of\udthe problems which arises in these systems is that of the limit\udcycle oscillations that occur due to quantization in the feedback\udloop. This paper investigates the limit cycle oscillations that occur\udin the digitally controlled version of the buck converter with a\udproportional-integral controller. The amplitude and frequency\udof the oscillations that may occur on two duty cycle levels are\udinvestigated and related to the controller gain parameters. The\udanalysis shows that it is not possible to guarantee that limit\udcycle oscillations on two levels will not occur simply by adjusting\udthe gain parameters, and yields a condition which will prevent\udoscillations on two levels from occurring.
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