Current mode control arrangement and method thereof

Control circuitry for providing a control signal in a pulse width modulating regulating power converter wherein an output parameter delivered by the converter is regulated to a desired value by pulse width modulation of current within the converter, the control circuitry including:

• circuitry for receiving a sensed output parameter of the converter;
• circuitry for deriving therefrom an analog average current demand signal corresponding to a current that would bring the converter into regulation;
• circuitry for receiving a sensed present value of the current within the converter to provide an analog signal representative thereof;
• circuitry for differencing the average current demand signal and the analog signal to provide an error signal;
• a compensator to which the error signal is applied, the compensator being arranged to average the error signal over time to provide a second error signal;
• a sawtooth generator for providing an analog signal as a pulse width modulation ramp;
• and
• a comparator to which the ramp is applied to generate the control signal at the output thereof;
• wherein both the error signal and the a second error signal are simultaneously applied to the comparator such that the error signals are additively compared to the ramp by the comparator.