EMI Suppression Filters (EMC and Noise Suppression) An Introduction to Noise Suppression in Onboard Ethernet 100Base-T1

3Radiation Noise Evaluation

Test Condition

The noise suppression effect of the common mode choke coil was confirmed with radiation noise measurements.

Measurement results

4Conductive Noise Evaluation

Test Condition

Test Board Circuit

Measurement results

Noise increases across some frequencies with the CAN and FlexRay compliant DLW43SH101XK2, and the noise suppression effect is insufficient. However, the noise can be effectively suppressed by using the 100Base-T1 compliantDLW43MH201XK2 別ウィンドウで開く

5DPI Evaluation

The immunity improvement effect of the common mode choke coil was confirmed by performing a DPI (Direct Power Injection) test.

Test Condition

Measurement results

6Summary

  • Because onboard Ethernet uses non-shielded cables which easily radiate noise and onboard noise standards must be supported, noise suppression is required.
  • CISPR25 Class5 radiation noise standards can be met by using the 100Base-T1 compliant DLW43MH201XK2.
    It displays a higher level of noise suppression for conductive noise and DPI than the common mode choke coils for CAN and FlexRay.