A digital current mode control technique for dc-dc converters

The objective of this paper is to propose a simple digital current mode control technique for dc-dc converters. It has been shown that we can implement any one of the average, peak and valley current mode controls by adjustment of the sampling instant of the inductor current with respect to the turn ON instant of the switch. Unlike other digital current mode control methods, the trajectory of the inductor current during the switching interval is not estimated in this method, and as a result the computational burden on the digital controller is significantly reduced. It therefore effectively increases the maximum switching frequency at which the converter can be switched when a particular digital signal processor is used to implement the control algorithm. The proposed digital current mode control algorithm is tested on a 12 V input and 1.5 V, 7 A output buck converter switched at 100 kHz and experimental results are presented.