Voltage Predictive Methods for Digitally Controlled Synchronous Buck Converter

Predictive control is widely used in dc-dc buck converters. With different control values, conventional voltage predictive control and average voltage predictive control are reviewed, respectively. The former has a fast transient response with high calculation burden and variable switching frequency. The transient response of the latter is slower. However, it has a constant switching frequency which reduces computations. For the average voltage predictive control, an improved method is proposed to limit the inductor current. Transient responses and stability are investigated under the two methods and compared with dual-loop proportional-integral-differential (PID) control. Simulation results under 12V/1V condition verify the effectiveness of voltage predictive control.