The Sampled-Data Modeling for Multiphase Constant On-Time Control-Phase Nonoverlapping

This paper investigates the application of the sampled-data modeling method for multiphase constant-on-time (COT) control with ramp compensation. Previous sampled-data models have only considered the case with zero slope compensation, revealing that the ratio of duty cycle perturbation to sensed current perturbation at the sampling instant-defined as the moment when the two input signals of the modulator intersect-remains constant. However, this paper found it invalid if non-zero slope compensation is introduced. Utilizing the principle of sampled-data modeling, this paper re-derives the modulator model and loop gain, then simplified expressions is obtained by further approximation. Finally, the accuracy of the proposed theoretical models is validated through experimental results.