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This paper deals with common mode electromagnetic interference (EMI) sensitivity of a high side current measurement curcuit. The usefulness of the needed input filter decreases with the component mismatch. The decreasing common mode attenuation is a problem for a lot of applications. Especially in the automotive environment impulses occur with high contribution between 1 MHz and 50 MHz. In order to realize an exact current measurement, there is a strong need of an input filter. A detailed simulation model of the high side current measurement curcuit based on analytical expressions allows the prediction of the common mode interference attenuation. It is shown that the introduction of a star circuit capacitor network in the filter structure can lower the influence of the tolerances of the components. The optimization of the circuit can be performed by simulation due to the reasonably good agreement with measurements.