Patent ID: 7259603

Claim:
A switch mode power converter comprising: a switching cell with a supply input, an output and a control input, a summing comparator having first and second differential input pairs and an output, the output being connected to the control input of the switching cell, an oscillator providing a periodic waveform that is applied to a first one of the inputs of the first differential input pair of the summing comparator, an adjustable reference voltage source providing an adjustable reference voltage a predetermined fraction of which is applied to a second one of the inputs of the first differential input pair of the summing comparator, and an error amplifier having differential outputs coupled to the second pair of differential inputs of the summing comparator and a differential input pair, a first input of said differential input pair being coupled to the output of the switching cell, the adjustable reference voltage from the adjustable reference voltage source being applied to a second input of said differential input pair.