Digitally‐assisted constant‐on‐time dynamic‐biasing technique for bandwidth and slew‐rate enhancement in ultra‐low‐power low‐dropout regulator

A digitally‐assisted constant‐on‐time dynamic‐biasing (COT‐DB) technique has been proposed to enable significant enhancement in dynamic performances, while the average current consumption can be kept to ultralow level. This dynamic‐biasing technique has a predefined magnitude and duration on biasing current boost, which is beneficial to estimate power budget in systems with finite energy source. The proposed technique has been applied to a low‐dropout regulator (LDO) to demonstrate the effectiveness. Experimental results show that significant improvements in settling times during load‐transients and line‐transients are as much as 880×, while the current consumption is only 1.02 μA. In fact, for the same dynamic performances, the average current consumption of LDO with COT‐DB technique can be as low as 0.39% of the LDO with heavy static biasing. The digitally‐assisted implementation of the technique also allows robust augmentation of the technique onto almost all analog systems. Copyright © 2015 John Wiley & Sons, Ltd.