The energy of lightning strikes can easily exceed a transceiver’s fault protection and must be absorbed by external TVS diodes. Two conditions must be satisfied when adding external TVS devices to an OVP transceiver: first, the TVS breakdown voltage must be 1 V higher than the highest common-mode voltage of the application or the maximum DC-supply, whichever is greater. For applications only exposed to the standard common-mode range of -7 V to +12 V, VBR-min ≥ 13 V, for bus lines running adjacent to DC power lines with 24 V nominal supply, VBR-min should be ≥ 31 V, as 24 V systems are known for excursions of up to 30 V. Second, the peak clamping voltage of the TVS must be below the transceiver’s maximum fault protection levels: VCL-max < VOVP-max. This slide shows the respective circuit and TVS switching characteristics with breakdown and clamping voltages, VBR and VCL, and compares them to the maximum common-mode range, DC-voltage, and fault protection levels.