Modeling of input dynamics of telecom load

This paper studies the input dynamics of a buck type converter with an input filter using voltage-mode and current-mode control at continuous inductor-current-mode. The relevant transfer functions are derived first without the input filter and the effect of the input filter is added by means of circuit theoretical manipulations. The transfer functions are analyzed in frequency domain. The effect of switching frequency as well as the propagation of rapidly varying load current pulses is studied using Matlab^TM. It is evident that the dynamic behavior of telecom load systems in the respect of EMC and the required dynamics of the down-stream power converter can cause severe problems, if the input filtering and controller design is not carefully considered