Improving Low-Dropout Regulator Frequency Stability by Exploiting the Equivalent Series Resistor and Featuring an Adaptive Biasing Strategy

This paper explores the impact of the equivalent series resistor (ESR) on the stability of linear regulators. While traditional compensation schemes seek to mitigate the effect of ESR on regulator performance, this paper shows the advantages of using ESR as a lag-lead compensator to improve phase and gain margin without regarding possible low ESR values. The work also presents an adaptive biasing strategy: 1) to reduce the variation of nondominant poles; 2) to improve efficiency for low load-currents.