Power MOSFETs Paralleling Operation for High Power High Density Converters

In high power high density converters, the power MOSFETs can be used in parallel as the main switch to meet the current rating requirement, increase the switching frequency, and reduce the power loss. This paper investigates the possible benefits and problems associated with the power MOSFETs paralleling operation for higher power high frequency applications. The conduction state current sharing and power loss are investigated considering the device junction temperature effect and conduction resistance mismatch. The switching transient current sharing is analyzed including the device parameters tolerance, power stage parasitic inductance and gate driving ability. A dynamic current sharing approach from the gate side is proposed. The experimental results indicate that the power MOSFETs can be paralleled with the proper gate driving design even if the device parameters are mismatched, and as a result the switching losses are significantly reduced