Highly accurate current measurement

摘要

The present document relates to the measurement of the current through a transistor. In particular, the present document relates to a circuit arrangement which allows an accurate measurement of the current through a power transistor. A circuit arrangement is described. The circuit arrangement is configured to provide an indication of a current flowing through a pass switch, when the pass switch is arranged in parallel to the circuit arrangement. The circuit arrangement comprises a matching unit which comprises a switch bank comprising a plurality of parallel reference switches; a resistor bank comprising a plurality of serial reference resistors; and a reference current source configured to provide a reference current flowing through the switch bank and the resistor bank. The resistor bank and the switch bank are arranged in series. The switch bank is adapted in accordance to a voltage dependent resistance of the pass switch, and the resistor bank is adapted in accordance to a voltage independent resistance of the pass switch.