Patent ID: 7999526

Claim:
A digital charge-mode controller for a switched power stage powering a load, the switched power stage having a converter with a duty cycle switch driven by a gate drive signal with a switching cycle having a duty cycle portion for controlling the power supplied by the power stage to the load, said controller comprising: an analog/digital converter configured to convert the current through the duty cycle switch to a switch current value; an accumulator module configured to add a slope compensation value to the switch current value, and to integrate the slope-compensated switch current value during the switching cycle and output an accumulated charge value; and a comparator module configured, responsive to the accumulated charge value and a charge set point, to generate the gate drive signal for the duty cycle switch that turns the duty cycle switch ON when the accumulated charge value is less than the charge set point and turns the duty cycle switch OFF when the accumulated charge value reaches the charge set point and thereby controls the duty cycle of the converter and the power supplied by the power stage.