Pulse Electronics ICMs Provide the Building Blocks of Gigabit Industrial Networks

Industrial networks control factory-floor equipment, transmit data and images to off-site monitors, and permit seamless local and remote communication and data transfer. The Ethernet technology underlying these networks has evolved over the years from 10BASE-T systems capable of transmitting 10 Mbps to networks that support up to 400 Gbps in both wired Ethernet and wireless 5G transmission. This evolution relies on network building blocks that connect devices to the local area network (LAN) via Ethernet cables, improve signal transmission, and manage the flow of data.

Designers can choose individual industrial network devices or products that combine optimal components in an easy-to-deploy package. Understanding the options is the first step toward implementing a future-proofed industrial network.

The building blocks of industrial connectivity

Each device in an industrial network has a physical layer (PHY), the Ethernet chips embedded in its printed circuit board (PCB). The PHY manages communication in and out of the device.

Data leaving the device typically travels over a physical medium, such as an Ethernet cable. The cable and PHY combined determine the transmission speed. Most new devices support at least 1000BASE-T Ethernet, meaning that the device can transmit or receive data at up to 1,000 Mbps or 1 Gb/sec over cabling comprised of multiple twisted pairs of wires.

Integrated connector modules (ICMs) sit between a PHY and transmission media and enable effective communication between the two. ICMs must supply media-dependent interfaces (MDIs), like standard RJ45 Ethernet jacks for cables to plug into. ICMs must also ensure electromagnetic compatibility (EMC) within the system by matching the impedances of the PHY and the cable and providing galvanic isolation that protects the connection from surges, ground loops, and signal noise.

A 1:1 transformer within the IMC also separates the direct current (DC) bias operating the PHY from the DC biases used to transmit data or power to connected devices via Power over Ethernet (PoE).

ICMs manage PoE by ensuring a DC bias between two twisted pairs used to transmit data or between two unused twisted pairs in the Ethernet cable. PoE can greatly simplify cabling for factory-floor applications, though careful selection of cables, ICMs, and other network building blocks is necessary to keep EMI to a minimum.

Putting PoE to work

To implement PoE in industrial settings, engineers use LAN transformers like those in Pulse Electronics’ PulseChip LAN Transformer TCxG series (Figure 1). These devices facilitate the baseband transmission of data at 1 Gbps, 2.5 Gbps, 5 Gbps, or 10 Gbps, as well as 0 to 90 W of DC power over four twisted pairs of wires.

Figure 1: PulseChip TCxG series LAN transformers pair with magnetic chokes to reduce signal noise and deliver 0 W to 90 W of DC PoE along with up to 10 Gbps of data. (Image source: Pulse Electronics)

The surface-mount device (SMD), ferrite-core transformers provide 1,500 V_RMS of galvanic isolation to reduce noise and EMI. The TCxG series meets or exceeds the relevant sections of the Institute for Electrical and Electronics Engineers’ (IEEE) 802.3 specification governing the electrical requirements of Ethernet and Wi-Fi communication devices, specifically the requirements for 1G, 2.5G, 5G, and 10GBASE-T Ethernet transmission and IEEE 802.3bt for type 4 class 6/8 PoE applications.

TCxG LAN transformers are designed to fit standard six-pad PCB layouts in the 1812 (4732) core size. The TCxG00P series manages 60 W of PoE in a 4.70 ±0.25 mm by 3.20 mm footprint. The TCxG001P series that handles 90 W is 4.60 ±0.25 mm by 3.40 mm, a size specifically designed to fit the small core layout, though Pulse Electronics engineers recommend providing extra room for the cable side of the transformer to mitigate temperature rise under the higher wattage. The transformers are designed to operate at temperatures between -40°C and +85°C, including temperatures induced by self-heating of the components.

Both designs feature less than -1 dB insertion loss at frequencies up to 200 MHz. To further reduce signal losses, the TCxG series transformers are designed to be paired with SMT magnetic chokes, such as Pulse Electronics’ PE-0805GCMC series. These chokes, which help filter electronic noise from the signal, are paired with the LAN transformers by data rate to ensure impedance matches. They fit a smaller 0805 (2012) core size at 2.00 mm by 1.2 mm, and, because they do not have polarity to restrict their placement, they offer flexibility in PCB design.

The flexible, modular design of the TCxG transformers and their paired chokes, as well as the transformers’ ability to carry PoE, make them ideal for applications like human-machine interfaces (HMI), industrial Ethernet LAN switches, routers and servers, and 5G and Wi-Fi wireless access points (WAPs).

Integrating connectivity with ICMs

While specifying LAN transformers and magnetic chokes separately provides flexibility, many applications call for an integrated solution. An ICM brings together a LAN transformer with magnetic chokes and with an RJ45 socket for the Ethernet cable plug while maintaining compatibility with commonly used PHY chips.

In Pulse Electronics’ Pulsejack JXT7 series of Ethernet ICMs (Figure 2), these components work together to deliver data rates up to 10 Gbps per IEEE 802.3an or achieve multi-rate 2.5 Gbps and 5 Gbps operation per IEEE 802.3bz. They can also deliver up to 140 W of DC power over a 100-ft run of unshielded twisted pair (UTP) cable, such as Cat5e or Cat6, per IEEE 802.3bt.

Figure 2: Pulsejack JXT7 series of ICMs combine a LAN transformer, magnetic chokes, and an RJ45 jack to support 1 Gbps to 10 Gbps data rates and up to 140 W of DC PoE in a ruggedized SMD ideal for WAPs. (Image source: Pulse Electronics)

To combat potential overheating at these higher power levels and currents of up to 1.3 A, JXT7 ICMs with overall dimensions of 34.29 mm deep by 16.51 mm wide by 13.33 mm tall provide a larger cavity design. The units’ ample EMI shielding includes top and bottom EMI fingers and extra grounding tags. JXT7 ICMs are ruggedly constructed for industrial and outdoor applications at temperatures from -40°C to +85°C.

Taking networking to the next level

ICMs are crucial building blocks to connect individual devices to an industrial Ethernet network, but building that network requires switches, routers, and antennas that can match the data rates the devices transmit. To maintain the space efficiency on the factory floor offered by compact ICMs and PoE technology, these networking devices need to fit existing PCB layouts.

One way to achieve this efficiency is with ball grid arrays (BGAs), SMDs that allow for high-density packing of networking components. Pulse Electronics’ 1-GB SMD BGA Ethernet LAN modules (Figure 3) support Ethernet connectivity from 10BASE-T through 1000BASE-T while delivering up to 70 W of DC PoE with less than 140 mm²/port density.

Figure 3: Pulse Electronics 1-GB SMD BGA Ethernet LAN modules can upgrade network switches to support greater levels of PoE while supporting data rates of up to 1 Gbps. (Image source: Pulse Electronics)

The units, which fit into the footprints of older components that support slower speeds or lower wattage, fit behind 2xN connectors, which have two rows of ports and one to eight ports per row. Modules designed for industrial environments are rated for operating temperatures from -40°C to +80°C.

These high-density modules can also support the addition of 5G antennas for wireless RF communication. Antenna Solutions for 5G Applications, such as those from Pulse Electronics (Figure 4), can be internal to a device on its PCB or flexible circuit board (FPC), or can be mounted externally with hardware or magnets. The choice of an antenna depends on the desired data-transmission rate and bandwidth, the distance to the receiver, and any obstacles in the way or interference.

These antennas support the low and mid-band of 5G transmission with frequencies from 617 MHz to 7,125 MHz. At these frequencies, they can transmit data from sensors to smart devices with high data rates and low latency.

Figure 4: Pulse Electronics 5G antennas support industrial networks over Wi-Fi, Bluetooth, and other RF communication standards across frequencies from 617 MHz to 7,125 MHz. (Image source: Pulse Electronics)

Conclusion

Industrial networks depend on a variety of components like LAN transformers, magnetic chokes, twisted-pair cables, Ethernet jacks, switches, routers, and antennas. When these components work together as designed, the industrial network of today and of the future supports multi-gigabit speeds with high accuracy and low latency.