A switching device and a method of operating a switching power element are disclosed for generating a train of drive pulses (D1 to D32) in a basic pattern for a repetition cycle time (T to TF) having leading time intervals (Th1 to Th3, Th1' to Th3'), associated with leading edges (a1 to a32) of the drive pulses, and trailing time intervals (Tl1 to Tl3, Tl1' to Tl3'), associated with trailing edges (b1 to b32) of the drive pulses, which are different from each other, whereby switching frequencies and associated harmonics, resulting from the leading edges and the trailing edges of the drive pulses, are diffused. A diffusion frequency, representing an inverse number of the repetition cycle time for the basic pattern is set to be higher than an audible frequency.