A Low-Dropout Regulator with Low ESR, Low Line Regulation and High Currency Efficiency Using Low Output-Resistance Voltage Buffer

Power management is necessary to reduce the standby power of portable electronics such as cellular phones, pagers, laptops, etc. The LDO (low- dropout regulator) is one of the most popular DC-DC converters widely used in power management and the demand for LDO is increasing by the growing demand for their applications. For Li-Ion battery of portable devices the input voltage generally varies from 2.7 V to 4.2 V, this paper demonstrates a 59 mA LDO with input voltage operating from 2 V to 3.52 V Simulated in 0.35 mum CMOS technology, the LDO only use 1 Omega effective series resistance (ESR). With a 2.3 muF output capacitor and quiescent current 56 muA, the maximum transient-output variation (overshoot voltage) is 58.98 mV with full-load step change of 59 mA.