10/100/1000 Ethernet, Inter-building Lightning Immunity

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10/100/1000 Ethernet, Inter-building Lightning Immunity



Design Notes:

Protection Application:
The data signals used in an Ethernet port vary between 1.0V and 2.5V, with a maximum data rate of 1000Mbps (or 1GB). Some 10GigE applications are also starting to be deployed. At these data rates, the capacitance of the suppressor needs to be taken into account. The signal lines to be protected from ESD and lightning transients include Tx+/- and Rx+/- for 10/100 BaseT and the signal pairs A+/A-, B+/B- etc for 1000BaseT and 10GigE.
Solution Description:
As shown at the left, a two-stage protection scheme should be used. In this case, an SEP Series SIDACtor and SP3050 TVS Diode Array can be used for GR-1089, Type 3b/5b lightning protection (1 kV, 200A, tP=2/10µs), ITU K.20/.21 Basic & YD/T 993 (1000V, 25, tP = 10/700-5/310) or ITU K.20/21 Enhanced (1500V, 37.5A, 10/700- 5/310), IEC 61000-4-5 Class 3 (2000 V,1000A, tP = 1.2/50- 8/20) as well as ESD protection (IEC 61000-4-2 15 kV air discharge, 8 kV contact discharge). The SEP diverts the majority of the energy away from the transformer while the SP3050 clamps the remaining“let-through” energy to safeguard the PHY.
Companion Solutions:
In the event that the Ethernet port has to comply with power fault requirements, then fuses like the 0461 Series should be considered. Also, devices like the SP4061 and SP4062 Series can be used in place of the SP3050 if more robust protection (i.e. lower clamping) is required.
Regulatory Issues:
GR-1089 (Inter-Building & Port Type 3b/5b), ITU K.20/21, YT/D 993, and IEC 61000-4-5 Class 3 provide the testing criteria for equipment that has Ethernet wiring exposed to outdoor environments.
Unique Features:
Application Warnings:

Solutions

Solutions

  • SP3050

    2pF, 20kV, Low Capacitance Diode Array for ESD and Surge Protection