Open-loop peak voltage feedforward control of PWM buck converter

DC and small-signal analyses are given for an open-loop buck pulse-width mo dulated (PWM) dc-dc converter with peak-voltage-modulation (PVM) feedforwar d control. A dc model is used to derive the de input-to-output voltage tran sfer function taking into account parasitic components, such as the MOSFET on-resistance, diode forward resistance, and diode offset voltage. A small- signal model is used to derive the audio susceptibility and the input imped ance. It is shown that ideally the audio susceptibility is zero and the inp ut impedance is frequency independent and negative for the buck converter w ith PVM feedforward control.