Disclosed is a system and method for synchronizing switching regulators in an electronic system so that switching interference from the regulators may be kept from a given spectral region of interest. The system does this by selecting a fundamental frequency such that each of the switching frequencies corresponding to each of the switching regulators is a harmonic of the fundamental frequency. Further, the fundamental frequency is selected so that none of the switching regulators, each of which are driven by an harmonic of the fundamental frequency, generates switching interference in the spectral region of interest. Each of the switching regulators has a synchronization clock, which multiplies or divides the master clock frequency by an allocated harmonic factor. Each harmonic factor is selected to that the switching frequency is within the operating range of the particular switching regulator.