A method is provided for scaling voltage in an integrated circuit. A calibration operation is performed on a functional module on the integrated circuit periodically at a rate T1. At least one parameter on the integrated circuit in monitored to determine when a performance threshold is reached. A change is initiated to an operating voltage for a portion of the integrated circuit in response to reaching the threshold. The rate of performing calibration operation is increased to a higher rate T2 for a window of time W in response to initiating the change in operating voltage, after which the rate of performing calibration is returned to the rate T1.