i min causing the switching circuit 106 to begin a new cycle by closing the third switch 206 and opening the fourth switch the operation of the voltage regulator 102 is similar in the buck boost mode in each cycle the inductor current is ramped up to the peak current i peak in the first phase of each cycle once this occurs the control circuit 110 in the second phase of each cycle opens the third switch 206 and closes the fourth switch 207 while the first switch 204 remains closed and the second switch 205 remains open causing the voltage across the inductor to change instantaneously to maintain current flow the current flowing through the inductor decreases until it reaches the minimum current i min causing the switching circuit 106 to begin a new cycle by closing the third switch 206 and opening the fourth switch the primary difference is that in the first cycle of the buck boost mode the minimum inductor current i min is reached while the unregulated voltage source 104 is connected directly to the load 108 through the inductor 202 whereas in the second and third cycles the minimum current i min is reached after the unregulated voltage source 104 is removed from the load however if the rate of discharge of the inductor current during the first cycle is higher because for example the difference between the input and output voltage is greater then the minimum current i min may also be reached after the unregulated voltage source 104 is removed from the input of the voltage regulator 102 in the buck mode the.