Capacitor cross coupled 2-phase buck converter
AssigneeChaoyang Semiconductor Jiangyin Technology Co., Ltd.
InventorArnaud Toni
Life of this patent
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Abstract
A buck converter uses flying capacitors and cross coupling. The flying capacitors reduce the voltage stress across the inductors and the devices, and may provide high efficiency at very low duty cycle ratios. In addition to the high efficiency performance, the converters may provide a significant reduction in area, since smaller inductors can be used compared to typical buck converters. An example of realization shows up to 90% efficiency at 0.5V output and 10 A load from a 3.6V input with small flying capacitors, compared to what is typically used in a switched capacitor converter.
Claims13
A multi-phase buck converter, comprising:
- a plurality of power conversion phases, each power conversion phase comprising a high side switch and a low side switch coupled in series between an input voltage and a lower voltage, a flying capacitor coupled between the high side switch and the low side switch, and an inductor having a first end coupled to a node between the low side switch and the flying capacitor, with a second end of the inductor coupled to a load and an output capacitor in parallel;
- and
- a plurality of cross-coupling switches, each cross coupling switch coupling a node between the high side switch and the flying capacitor of one phase to the node between the low side switch and the flying capacitor of another phase.
A method of operating a multi-phase buck converter having a plurality of power conversion phases, each of the power conversion phases having a flying capacitor in series between a high side switch and a low side switch, with an inductor having a first end coupled to a node between the flying capacitor and the low side switch and having a second end coupled to a load in parallel to an output capacitor, the method comprising:
- during one time period, coupling the first end of the inductor of one phase with a node between the high side switch and the flying capacitor of another phase;
- and
- during another time period, not coupling the first end of the inductor of one phase with the node between the high side switch and the flying capacitor of the other phase.
Dependencies are inferred from the claim text.