Optimum power-saving method for power MOSFET width of one-cyde control DC-DC converters

An optimum power MOSFET width technique is proposed in this paper for enhancing the efficiency characteristics of switching DC-DC converters. By implementing a one-cycle buck DC-DC converter, we demonstrate that the dynamic power MOSFET width controlling technique has much improvement in power reduction when the load current is light or heavy. The maximum efficiency of the buck converter is about 92% with 3% efficiency improvement for the heavy load condition. Besides, the efficiency can be enormously improved about 16% for light load condition as a result of the power reduction from the large power MOSFET transistors. Meanwhile, we also propose a new error correction loop circuit (ECL) to get a better load regulation than that of the previous designs. Furthermore, as compared to the adaptive gate driver voltage technique, the optimum power MOSFET width can achieve a great improvement on power saving. It is a better power-saving technique than the low-voltage-swing MOSFET gate drive technique for switching DC-DC converters.