Low-Dropout Regulators With Adaptive Reference Control and Dynamic Push-Pull Techniques for Enhancing Transient Performance

Abstract

An adaptive reference control (ARC) technique is proposed for minimizing overshoot/undershoot voltage and settling time of low-dropout regulators. Linear operation provided by the ARC technique can dynamically and smoothly adjust the reference voltage so as to increase the slew rate of error amplifier thus forcing the output voltage back to its steady-state value rapidly. The amount of transient revision is proportional to transient state output voltage variation and load condition. In addition, a dynamic push-pull technique is used to enhance transient response. Experimental results demonstrate that the undershoot voltage, settling time, and load regulation are improved by 31%, 68.5%, and 70%, respectively, when load current changes between 1 and 100 mA.