US Patent 7940033 Control loop for switching power converters

A pulse regulation loop for a clocked switching power converter where the loop is around a bridge converter. The loop features a comparator, a charge pump and a filter in series, feeding a pulse modulator controlling the clock duty cycle of the bridge. Ripple in the bridge converter output is feed to the comparator which causes the charge pump to inject or remove charge from the filter at the clock rate providing control over the modulator that establishes converter efficiency. The charge pump is of the PLL type, having switches responsive to voltage output from the comparator, evaluating the converter ripple relative to a reference voltage.