Multi-phase critical conduction power converter and control method thereof

Abstract

The invention discloses a multi-phase critical conduction power converter and a control method thereof; a single-phase critical conduction converter is popularized to multiple phases; and the enablingstates of a plurality of power-stage circuits are controlled along with the change of a load current, so that the switching frequency can be maintained within a preset range when the load current ischanged. The defects of low working frequency and large conduction current of a single-phase critical conduction mode converter during heavy load are overcome; meanwhile, the defects that the workingfrequency is increased and the frequency is lowered of a multi-phase critical conduction mode converter in light load are also overcome. Meanwhile, during single-phase light load, the working frequency of the single-phase converter is reduced through a current intermittent mode, so that the multi-phase converter can keep efficient operation within the whole load range.

Description

technical field [0001] The invention relates to a power electronic technology, more specifically, to a multi-phase critical conduction power converter. Background technique [0002] With the development of CPU, GPU, and AI chips, low-voltage, high-current, high-efficiency, and small-volume core power supply circuits are required. The problems brought about by miniaturization are the increase of switching frequency, the increase of switching loss, and the decrease of efficiency. [0003] The working mode of current critical conduction enables the upper tube of the power converter to realize zero-voltage turn-on, which reduces the conduction loss, so that the power converter can work at a higher switching frequency under the condition of the same efficiency. However, due to the current critical conduction mode, the switching frequency varies widely with the load, which is not conducive to the improvement of efficiency in the full load range. Contents of the invention [00...

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Problems solved by technology

[0004] In view of this, the present invention provides a multi-phase critical conduction power converter, which extends the single-phase critical conduction converter to multiple phases, and solves the problem of low operating frequency of single-phase critical conduction mode converters at high loads. The disadvantage of large conduction current; the disadvantage of high operating frequency and low efficiency of the multi-phase critical conduction mode converter under light load

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