Würth Elektronik has published a circuit layout for a filter with transformers as galvanic isolation for single pair Ethernet links in industrial applications.
The filter design has isolation of 1.5 kV/60 s and is therefore fully suitable for industrial applications, unlike previous circuits that use two 50 V capacitors as galvanic isolation. The filter design is compact as the WE-STST transmitter series has a footprint of 4.5x3.2mm and provides signal stability of up to 40m cable length for 100BASE-T1 or up to 1 000 m for 10BASE-T1.
Alongside the WE-STST transmitter, a common mode choke, the WE-CNSW current-compensated data line filter, improves the EMC behavior already at frequencies from 1MHz without negatively affecting the useful signal. A TVS diode (WE-TVS) provides ESD protection to IEC 61000-4-2 up to 8 kV.
Würth Elektronik - www.we-online.com