A digitally controlled integrated DC-DC converter with transient suppression

A fully integrated DC-DC converter with digitally controlled dual output stages is introduced in this paper. An auxiliary output stage is added in parallel to the main output switching stage to mitigate the trade-off between fast load transient response and high power conversion efficiency. A 12V-to-1V, 3W voltage-control-mode prototype converter is designed and fabricated with TSMC 0.25µm 40V process. Experimental result shows that this method can reduce the transient overshoot by 50% and recovery time by 80% while maintaining similar efficiency when comparing to a conventional single-stage converter. The auxiliary stage imposed less than 20% area overhead.