Using modified z-transforms to model the step response of the peak current-mode controlled buck converter

Modified z-transforms were used previously to derive a z-domain transfer function for the peak current-mode controlled buck converter. This paper derives the relationships between the poles in the z-domain transfer function and the step response in the time domain. This will allow practical implementation of the modified z-transform model so that time domain parameters like overshoot and settling time can be determined. This paper experimentally verifies the model in the time domain by using the changes in the duty cycle of the gate waveform during the transient response to a step change in the control voltage.