Patent ID: 7723967

Claim:
A step-up converter comprising: input terminals configured to receive an input DC voltage and output terminals configured to provide an output DC voltage; step-up conversion circuitry coupled between the input terminals and the output terminals, the step-up conversion circuitry including a switching element; a first feedback path having a regulator arrangement configured to provide a regulating signal that is dependent on the output voltage; a drive circuit which is configured to provide a pulse-width-modulated drive signal for the switching element and is supplied with the regulating signal, wherein the drive circuit is configured to generate the drive signal in a manner that corresponds to the input voltage; and a second feedback path having a load change detection circuit configured to detect a sudden change in the output voltage and to operably provide a sudden load change signal which is dependent on such a detection at least indirectly to the drive circuit; and wherein the drive circuit is operably coupled to receive an input signal that is dependent on the input voltage, and wherein the drive circuit is further configured to generate the drive signal based on the input signal; and the drive circuit comprises a ramp signal generation circuit configured to receive the input signal and to generate a periodic ramp signal having a characteristic that is dependent on the input signal, and a comparator arrangement which generates the drive signal in a manner dependent on a comparison of the ramp signal with the regulating signal.