Single Pair Ethernet 1.5KV Electrical Isolation: Today, Ethernet is the most widely used protocol in industrial communication. Copper cables with two pairs for Fast Ethernet and four pairs for Gigabit Ethernet are the core elements to make data communication in company and industrial networks possible.
Coming from the automotive sector, Single-Pair-Ethernet (SPE) is now taking the leap to conquer the industrial world as well. Würth Elektronik is part of the SPE Industrial Partner Network initiative and is committed to making SPE usable for industrial applications – for example to replace analog sensor applications or bus systems.
RELATED: SINGLE PAIR ETHERNET ALLIANCE AND APPLICATIONS
By using only one pair of wires, the weight is reduced by up to 30 percent.
The challenge: SPE technology for automobiles cannot be adopted one-to-one for industrial applications, since the requirements for cable lengths and device safety are higher in industry.
The solution: Würth Elektronik has developed the first SPE circuit suitable for industrial applications that is fully compatible with the IEEE 802.3 signal requirements and the requirement for 1.5 kV safety insulation according to IEC 62368-1. The solution for 10BASE-T1 and 100BASE-T1 is compact and powerful with signal stability up to 1,000 m cable length.
Würth Elektronik advises on the use of SPE in industrial environments. With its components and an optimized compact circuit layout, Würth Elektronik provides powerful solutions with the best characteristics in terms of signal quality, EMC and ESD protection.
The circuit diagram for 100BASE-T1 Single Pair Ethernet commonly used in automotive applications consists of a common mode choke, two capacitors connected in parallel and a termination network for common mode interference.
However, the capacitors with 50 Volt electrical isolation are not sufficient for the electrical isolation of 1.5 kV/60 s according to IEC 62368-1 which is common in industry. Würth Elektronik’s innovative approach: Instead of using two capacitors, the galvanic isolation is provided by a signal transformer.
The WE-STST transmitter series is perfect for this application. It combines excellent performance with a very compact design of only 4.5 x 3.2 mm. By connecting the transformer center tap to GND, common mode signals are also effectively derived.
In addition to the transformer WE-STST, the current-compensated data line filter WE-CNSW improves the EMC behaviour already at frequencies from 1 MHz without negatively affecting the useful signal. A TVS diode (WE-TVS) provides ESD protection according to IEC 61000-4-2 up to 8 kV.
Further information about the industrial use of Singe Pair Ethernet can be found on the Würth Elektronik homepage and in the webinar recording on the topic “Single Pair Ethernet – Filter Design”.
