Sensorless optimization of dead times in DC-DC converters with synchronous rectifiers

This paper introduces an approach to achieve optimum dead times in dc-dc converters with synchronous rectifiers without sensing any of the power-stage signals other than the output voltage. The dead times are adjusted adaptively to minimize the duty-cycle command, which results in maximization of the converter efficiency. The method is particularly well suited for digital controller implementation, requiring no additional analog components or modifications of standard gate-drive circuitry. Experimental results for a digitally controlled 5V-to-1V, 5-A synchronous buck converter demonstrate practical implementation of the sensorless dead-time optimization algorithm.