Patent ID: 8203323

Claim:
An electronic device for switched mode DC-DC conversion comprising a stage for sensing an output current causing a voltage difference between a first and a second node, wherein the current sensing stage comprises a comparator being capacitively coupled with a first input to the first node and with a second input to the second node for determining a magnitude of the output current, wherein a first capacitor is coupled in series to the first input of the comparator and a second capacitor is coupled in series to the second input of the comparator, a first switch is coupled between one side of the first capacitor and the first node and a second switch is coupled between the first side of the first capacitor and a first side of the second capacitor for alternately connecting the first side of the first capacitor to the first node or to the first side of the second capacitor, further comprising a third switch and a fourth switch for coupling a second side of the first capacitor and a second side of the second capacitor to a common mode voltage node and a fifth switch coupled between the second side of the first capacitor and the first input of the comparator and a sixth switch coupled between the second side of the second capacitor and the second input of the comparator, the first, fifth and sixth switches being operated by a first clock signal, the second, third and fourth switches being operated by a second clock signal, the second clock signal being of opposite phase to the first clock signal, wherein during a first phase of the first clock signal the voltage difference across the first and second nodes is sampled and during the first phase of the second signal the first and second capacitors are not discharged and are coupled to a common mode voltage.