Patent ID: 7564700

Claim:
A switched power supply comprising: input terminals for receiving electric power and output terminals for delivering an output signal having an output voltage and an output current; wherein the input terminals are separated from the output terminals by an insulation barrier so that the input terminals are provided on a primary side of the insulation barrier and the output terminals are provided on a secondary side of the insulation barrier; a converter stage coupled between the input terminals and the output terminals, the converter stage having at least one controllable first switching element for generating a converter state duty cycle so as to cause the converter stage to generate the output signal; and a digital circuit for controlling the switching element in dependence of at least one signal, wherein the digital circuit is located on the primary side of the insulation barrier, and the switched mode power supply further comprises an amplifier located on the secondary side and arranged to receive the output voltage on a first amplifier input and produce an amplifier output signal that is to be transferred across the insulation barrier to the digital circuit, wherein the digital circuit is a programmable digital circuit comprising a processing means, a working memory, and an at least partly non-volatile memory for storing executable commands, and that the amplifier is frequency dependant having a transfer function characteristic that amplifies higher frequency components relative to the lower frequency components.