A Cap-less LDO Regulator with Improved Load Regulation using Adaptive Feedback Control and Modified Voltage Damper

This paper proposes a cap-less low-dropout (LDO) regulator using the Adaptive feedback control and the modified Voltage damper with the dual power transistors. To enhance the current efficiency, the main power transistor and the related low-impedance (LI) buffer are turned off by the Adaptive feedback control circuit and the Switch circuit to save the power at the light load. In addition, the modified Voltage damper is used to improve the undershoot transient response without extra static current. The proposed design is fabricated using a typical 0.18 mu m CMOS process. The quiescent current is decreased to 18.32 mu A. The peak current efficiency is simulated to be 99.97% with the load regulation of 0.082 mV/mA.