Comparative study of digital control sc...

The increasing amount of required functionality in today’s electronic devices demands for more advanced power supply concepts. A possible solution to increase the performance and efficiency of DC-DC converters is to use multi-phase topologies. These converters employ multiple parallel power stages, hence sharing the total load current. In order to provide a regulated output voltage and equal sharing of the total current, a control loop is an essential part of such a converter. This paper presents three digital control schemes for multi-phase buck converters, namely, a linear voltage mode controller, a combined Ton/Toff control and a non-linear sliding mode control (SMC) law. Experimental results of a two-phase buck converter highlight the effectiveness of more sophisticated controllers and the benefits of multi-phase over single-phase converters.