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¿V/V and 5.3¿V/mA, the overshoot and undershoot of the output voltage are less than 50mV when the load step changes in 0.1¿s, while the dropout voltage is 120mV at 150mA load current.