Highly Efficient VRM For Wide Load Range with Dynamic Non-Uniform Current Sharing

Multiphase converters are widely used especially in powering high-current loads. These converters are conventionally designed with symmetric phases and equal/uniform current sharing. This paper presents a multiphase VRM utilizing the concept of dynamic non-uniform current sharing between non-uniform phases. It is shown in this paper that high efficiency conversion can be achieved over wider load range with non-uniform phase design in multiphase converters and by utilizing the control scheme of dynamically varied non-uniform current sharing ratio between the interleaved phases. It is also shown that the proposed concept does not necessarily cause the increase in the size and cost of VRM design. The concept can be further expanded to the designs of other power stages such as AC-DC and PFC converters, bus converters and isolated or non-isolated converters. Theoretical and experimental results are provided in this paper, and they are compared with conventional symmetric designs with uniform current sharing.