Single-inductor bipolar-output power converting circuit and related control method

A method of controlling a single-inductor bipolar-output (SIBO) power converting circuit which comprises an input end for receiving an input voltage, a first output end for outputting a first output voltage, a second output end for outputting a second output voltage, a first node, a second node, a third node, a first switch coupled between the input end and the first node, a second switch coupled between the second node and a ground level, a third switch coupled between the third node and the ground level, a fourth switch coupled between the third node and the first output end, a fifth switch coupled between the second node and the second output end, a first flying capacitor coupled between the first node and the second node, an inductor coupled between the first node and the third node, a first capacitor coupled between the first output end and the ground level, and a second capacitor coupled between the second output end and the ground level, comprising:

• turning on the first switch, the second switch and the third switch and turning off the fourth switch and the fifth switch during a first operation phase, thereby allowing the input voltage to charge the inductor and the first flying capacitor;
• turning on the first switch and the fourth switch and turning off the second switch, the third switch and the fifth switch during a second operation phase, thereby allowing energy stored in the inductor to charge the first capacitor for establishing the first output voltage at the first output end;
• and
• turning on the third switch and the fifth switch and turning off the first switch, the second switch and the fourth switch during a third operation phase, thereby allowing energy stored in the inductor and the first flying capacitor to charge the second capacitor for establishing the second output voltage at the second output end.