High-Performance Low-Dropout Regulator Achieved by Fast Transient Mechanism

Abstract

An adaptive reference control (ARC) technique is proposed for minimizing overshoot/undershoot voltage and settling time of low-dropout regulators (LDO). Linear operation provided by ARC technique can dynamically and smoothly adjust the reference voltage for increasing slew rate of error amplifier and forcing 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, dynamic push-pull technique is used to enhance transient response. Experimental results demonstrate the undershoot voltage, settling time and load regulation are improved 31%, 68.5% and 70% when load current changes between 1 mA and 100 mA.