Digital Autotuning of DC-DC Converters Based on a Model Reference Impulse Response

This paper proposes a model reference-based auto-tuning technique for digitally controlled voltage-mode dc-dc converters. The proposed solution performs a comparison between the measured system impulse response and a reference derived from the desired dynamic performances, and minimizes the error function acting on the regulator parameters. Two different approaches are investigated to evaluate the impulse response: a deterministic tuning, injecting a duty-cycle impulse, and a statistical tuning, based on white noise injection in the control loop. Compared to existing approaches, this solution has the advantages of simplicity, small-signal processing, and on-line tuning capabilities. Experimental investigation is performed on a 20-A, 1.5-V digitally controlled synchronous buck converter, and both simulations and experimental results confirm the effectiveness of the proposed solution.