Fast-transient DC-DC converter using a high-performance error amplifier with a rapid output-voltage control technique

This letter presents a method for improving the transient response of DC-DC converters. The proposed technique replaces the conventional error amplifier with a combination of two different amplifiers to achieve a high loop gain and high slew rate. In addition, a rapid output-voltage control circuit is employed to further reduce the recovery time. The proposed technique was applied to a four-phase buck converter, and the chip was implemented using a 0.18-mu m CMOS process. The switching frequency of each phase was set at 2 MHz. Using a supply voltage of 2.7-5.5 V and an output voltage of 0.6-1.5 V, the regulator provided up to 2-A load current with maximum measured recovery time of only 6.2 and 6.5 mu s for increasing and decreasing load current, respectively. Copyright (C) 2017 John Wiley & Sons, Ltd.