3.3.5.3.3 Current Sensor Inputs Configuration when Using Rogowski Coil

The Rogowski Coil is a sensor used for the measurement of the current. This class of coils achieves very good results even for currents with a large variation range. However, they generate an output signal in the time-differentiated form. In this case, an integrator function (available in the Microchip metrology library running in Core 1) must be added to get the corresponding current value.

Figure 3-17. IPx and INx Current Sense Schematic when Using Rogowski Coil
When using Rogowski coils for current sensing, a two pole anti-aliasing filter must be mounted. The filter must be tuned with the following component values:
  • RA1, RA2 = Do Not Populate
  • RB1, RB2 = 100Ω, 1%, 25 ppm/ºC
  • RC1, RC2 = 3 kΩ, 1%, 25 ppm/ºC
  • CA1, CA2 = 47 pF Y7R
  • CB1, CB2 = 2.2 nF NP0/COG
  • CC1, CC2 = 3.3 nF NP0/COG
  • D1, D2 = Si Junction diodes (recommended)