Improving Transient Performance for Voltage Regulators with Error Amplifier Voltage Positioning

Next generation microprocessor requirements for high current slew rates and fast transient response together with low output voltages have posed great challenges on voltage regulator (VR) design. This paper presents a new error amplifier voltage positioning (EAVP) method which has proven to be effective in achieving fast transient response for voltage regulators. Unlike prior arts of non-linear control methods, it does not modify the power stage nor change the control loop gain. Instead, it helps error amplifier recover from its saturation status during transient events. Operational mechanism of the EAVP is presented in this paper in detail. Simulation results and experimental data show that the EAVP scheme settles down the output voltage quickly after a heavy load transition, resulting in excellent transient performance without impact on other operations.