A method includes comparing, by a voltage-second (VS) controller, a first duty cycle used to control a first switch at a primary side of a power transformer of a DC-to-DC converter with a threshold. The method further includes if a value of the first duty cycle is less than the threshold, controlling, by the VS controller, a second duty cycle used to control a second switch at a secondary side of the power transformer, and maintaining a voltage level at an output voltage node at a non-zero value, and if the value of the first duty cycle is greater than the threshold, controlling, by an output voltage loop, the second duty cycle based on the first duty cycle, and monotonically increasing the voltage level the at the output voltage node from the non-zero value to a predetermined value..