Predictable Auxiliary Switching Strategy to Improve Unloading Transient Response Performance for DC–DC Buck Converter

Implementation of Soft-Switching Auxiliary Current Control for Faster Load Transient Response

“…Fig. 8 shows the waveform of the stepping-up iO and corresponding iL1+iL2 of the proposed method, controlled auxiliary current (CAC) scheme [19]- [21], and current-programmed mode (CPM) scheme [22]- [24] with the same L2 and ∆td. Obviously, the area A1 determines ∆vO.…”

“…In this section, the estimated power losses of the auxiliary converters are compared. The CAC [19]- [21] and CPM [22]- [24] schemes were again selected as the conventional counterparts due to their similarity to the proposed control: nonresistive auxiliary circuits and the auxiliary current that is controlled to satisfy CCB. All conditions except that the constant switching frequency of the CAC and CPM is 2 MHz were held the same with the proposed method for a fair comparison.…”

“…This concept was later extended to the multiphase buck converter with the peak current mode (PCM) control [17]- [18]. Works shown in [19]- [21] control the average current of the auxiliary inductor to secure CCB during the load transient. An adaptive slope control discussed in [22]- [24] also maintains the CCB to further improve the load transient response.…”

“…The prior arts [19]- [24] are similar to the proposed technique since they also control the inductor current of the auxiliary buck converter. The proposed technique outperforms these approaches by improving the efficiency of the auxiliary converter while maintaining the same dynamic performance.…”

Minimum charge-recovery time control with parallel connected buck converters

“…The slew-rate of buck converters is primarily limited by their inductors, and methods based on increasing the voltage across the inductor or changing the inductance value during transient conditions, have been reported [1,2] to improve the transient response. One example is the augmented converter [3], where a resistive path is enabled during the transient condition to allow extra charge to be provided to the load or absorbed by a dummy burden resistor. Although this modification improves the response time, it is at the expense of efficiency.…”