Dynamic Slew Enhancement Technique for Improving Transient Response in an Adaptively Biased Low-Dropout Regulator

This brief presents a dynamic slew enhancement technique for improving the transient response in an adaptively biased low-dropout regulator. This is done by introducing FAST and SLOW paths in an adaptive bias loop. The FAST path injects a quick momentary current during a low-to-high load transient, whereas the SLOW path keeps the current large during a high-to-low load step. The dynamic current shoots up to quite a high level as it is combined with adaptive biasing. When the proposed technique is implemented in the 0.18-mu m CMOS technology, the experimental results show the effective reduction in the undershoot (67%) and the overshoot (66.7%) while maintaining a low quiescent current of 1.1 mu A. The settling times during 0-50-mA and 50-0-mA load transients are improved by 74% and 99.9%, respectively.