| 摘要 |
A single inductor multiple output buck converter includes an inductor having a first terminal and a second terminal, a first switch coupled between an input voltage and the first terminal of the inductor, a second switch coupled between the first terminal of the inductor and a reference ground, a third switch coupled between the second terminal of the inductor and a first output voltage, and a fourth switch coupled between the second terminal of the inductor and a second output voltage. A first feedback signal indicative of the first output voltage is compared with a first reference signal to generate a first comparison signal. A second feedback signal indicative of the second output voltage is compared with a second reference signal to generate a second comparison signal. Then which one of the first comparison signal and the second comparison signal is asserted first is detected, and the first to fourth switches are controlled based on the detection result. |
| 主权项 |
1. A control method of a single inductor multiple output buck converter, wherein the single inductor multiple output buck converter comprises an inductor having a first terminal and a second terminal, a first switch coupled between an input voltage and the first terminal of the inductor, a second switch coupled between the first terminal of the inductor and a reference ground, a third switch coupled between the second terminal of the inductor and a first output voltage, a fourth switch coupled between the second terminal of the inductor and a second output voltage, a first capacitor coupled between the first output voltage and the reference ground, and a second capacitor coupled between the second output voltage and the reference ground, and wherein the control method comprises:
generating a first feedback signal based on the first output voltage; generating a second feedback signal based on the second output voltage; comparing the first feedback signal with a first reference signal and generating a first comparison signal; comparing the second feedback signal with a second reference signal and generating a second comparison signal; detecting which one of the first comparison signal and the second comparison signal is asserted first; and controlling the first switch, second switch, third switch and fourth switch based on the detection result; wherein when the first comparison signal is asserted earlier than the second comparison signal, the first switch and the third switch are turned on, the second switch and the fourth switch are turned off, wherein the first switch will be turned off and the second switch will be turned on once the on time of the first switch reaches a first time threshold; when the second comparison signal is asserted earlier than the first comparison signal, the first switch and the fourth switch are turned on, the second switch and the third switch are turned off, wherein the first switch will be turned off and the second switch will be turned on once the on time of the first switch reaches a second time threshold. |
