Transient response in a buck converter with bulk decoupling capacitors employing load current feedforward control

To improve the dynamic regulation of the power supplies, several applications of the load current feedforward control have been reported. This paper presents the characteristics of the transient response of a buck-type DC-DC converter employing load current feedforward control when the large decoupling capacitor is added to the load parallel. In this case, the load is generally capacitive and its large capacitor is called a bulk capacitor. Considering the bulk capacitor and the line impedance, the dynamic behaviors of the converter have been analyzed to investigate the influence upon the effectiveness of the feedforward control. Furthermore, the instability encountered by the bulk capacitor is discussed.