High PSR Low Power Negative-R-Assisted LDO

A Low-Dropout Regulator with adaptive low power mode and negative-R assisted technique is proposed in this paper. Two designs namely, adaptive low power mode to dynamically adjust power consumption under different load conditions and, negative-R assisted technique to improve the stability and transient response, have been simulated on Cadence virtuoso using 45nm technology. For both designs, an output voltage of 1V has been achieved for an input voltage of 1.2V. Furthermore, study has been done on both the LDOs transient response for varying loads. Also line regulation, load regulation, PSR and stability analysis have been carried out for both the designs. The PSR is found to be 50% better than the existing work and both the circuits are found to have good load and line regulation.