Patent ID: 7157963

Claim:
A method of controlling the power supply voltage in a multi-phase switched-mode power supply for an amplifier comprising: (a) receiving an input signal representative of a desired power supply voltage over a predetermined time period, (b) processing the input signal to derive a phase value indicative of the number of power supply phases which should be enabled to achieve the desired power supply voltage, and (c) outputting a phase signal for activating only the number of phases indicated by the phase value, for substantially the predetermined time, the method further comprising receiving a series of said input signals related respectively to a series of said predetermined time periods, arranging for said phase signal to select the phases to be activated in each time period, recording any error between the desired power supply voltage and an actual power supply voltage produced by the switched-mode power supply and feeding an error signal forward into the next time period to adjust the next phase signal to take account of the recorded error.