Modelling and validation of high-current surface-mount current-sense resistor

A lumped-element model of a 50-mΩ, 10-W surface-mount current-sense resistor is extracted and its parameters are presented. The model parameters are optimized to fit the measured impedance characteristics. The extracted model is valid up to 100 MHz and it consists of frequency-independent components. The model is validated by measurements and the reproduced current waveform is compared to the one obtained by a commercial large-bandwidth current sensor. The comparison of the extracted model and nominal 50-mΩ model is presented. The extracted model shows significantly better correlation to the commercial current sensor than the nominal 50-mΩ model, especially for larger currents and higher frequencies.