205 the first switch 2 is turned off for the rest of the current clock cycle and the subsequent clock cycle is waited when the first switch 2 is again turned on if instead the protection threshold is not exceeded output no from step 205 the next clock cycle is waited and the dc dc converter 30 is subjected only to the voltage regulation carried out by the components 19 16 20 fig9 shows in detail step 106 initially the protection intervention detector 31 waits for the time t m step 300 then the value of the threshold overstepping signal ocp is detected step 301 if the current i l exceeds the preset protection threshold threshold overstepping signal ocp active output yes from step 301 the first switch 2 is turned off for the residual duration of the current clock cycle step 302 and the variable counter_jump is set at n 1 step 303 as is the variable n step 304 then in the next n 1 clock cycles the first switch 2 is kept off in this way the on off rate is reduced if instead the protection threshold is not exceeded by the time t m output no from step 301.