A system and method is disclosed for rapidly increasing a rising slew rate of an adjustable power supply signal in an adaptive voltage scaling system. When a central processing unit of an adaptive voltage scaling system requests an increase in a performance level, a closed loop control mode of the adaptive voltage scaling system is disabled. Then a value of voltage that corresponds to the requested increased performance level is provided as a voltage change command to an adaptive voltage scaling regulator. The adaptive voltage scaling system is then operated at a maximum slew rate that can be achieved by the adaptive voltage scaling regulator. The closed loop mode is enabled after the adjustable power supply voltage reaches the requested voltage value.