A General Framework for Automated Tuning of Digital Controllers in Multi-phase Dc-Dc Converters

Digital controllers are widely used in interleaved multi-phase dc-dc converters. The inherent nonlinearities introduced by the nonlinear control rules, quantizers, and mapping between analog and digital domains complicates the controller design process. A simple, yet accurate auto-tuning framework is set forth that provides the required controller coefficients to meet desired time and frequency performance criteria. This is an optimization-based process which minimizes a cost function formulated using error terms. The proposed methodology is implemented on a dual-phase buck converter with a regulated output voltage and drastic change in the load current. The desired performance is verified in time and frequency domains using hardware measurements and numerical simulations.