High-accuracy low-dropout voltage regulator based on slow-rolloff frequency compensation

High-stability, high-accuracy low-dropout (LDO) voltage regulators are presented. The proposed LDOs make use of the slow-rolloff frequency compensation scheme which can enhance the stability, increase the loop gain and unit-gain frequency (UGF). This scheme is realized by introducing a dominant half-pole by virtue of three zero-pole pairs and a low-frequency pole. Post-layout simulation results show that these LDOs have robust stability, high open-loop gain and UGF, which lead to excellent regulation and transient response performance. The line and load regulation are 81 mu V/V and 5.3 mu V/mA, the overshoot and undershoot of the output voltage are less than 50mV when the load step changes in 0.1 mu s, while the dropout voltage is 120mV at 150mA load current.