Microchip Ethernet Connects for Reliable and Secure Connectivity

Ethernet Networking and Connectivity

We are in a truly connected world, and one of the most ubiquitous and dependable connectivity technologies is Ethernet—a family of wired computer networking technologies has been around for over 40 years, and it continues to evolve and advance in an astonishing way. No longer just the blue cable that connects you to the internet, Ethernet has found a home in just about every market space you can imagine: everything from a robotic arm on the factory floor to a satellite that looks down at the Earth from millions of miles away. Ethernet is a powerful technology and engineers, designers, systems architects, makers and creatives all over the world are reimagining how to use this technology.

You may wonder what exactly Ethernet is all about and how it has become one of the most trusted standards for networking connectivity. There’s a lot to unpack here, as we could delve into Ethernet switches, controllers, bridges, etc., but for now, let’s examine Ethernet Physical Layer Devices (PHYs), how they work and why they’re important.

Ethernet PHYs

In Ethernet technology, the implementation of a specific physical layer is commonly referred to as PHY, and Ethernet transceivers are the physical layer (PHY) specifications of the Ethernet family of computer network standards as defined by the Institute of Electrical and Electronics Engineers (IEEE^®). Two of the most common cable types utilized in wired networks are copper-based PHYs and optical PHYs. Both have their advantages and disadvantages and choosing which one to use depends on your application needs and requirements. We’ll look at both physical media options, with a special focus on optical PHYs and our latest optical PHY offering.

Copper Ethernet PHYs

A copper PHY is an integrated circuit or module that implements the physical later functions for Ethernet communication over copper cabling, typically twisted-pair cables such as Cat5e, Cat6 or Cat7. The PHY is responsible for encoding, decoding, transmitting and receiving electrical signals that represent digital data over copper wires.

Key functions of a copper PHY include:

• Signal encoding/decoding: Converts digital data from the Media Access Controller (MAC) into electrical signals suitable for transmission over copper cables, and vice versa
• Auto-negotiation: Determines the best speed and duplex mode supported by both ends of the link such as 10/100/1000 Mbps, full/half duplex
• Link-integrity monitoring: Continuously checks the status of the physical connection and reports link status to the MAC
• Physical medium attachment: Interfaces typically through an isolation transformer with the copper cable, handling the electrical characteristics required for reliable data transmission

Common applications for copper PHYs are network equipment such as Ethernet switches and routers; embedded systems, where microcontrollers and processors integrate or connect to external copper PHYs for network connectivity; and industrial and automotive networking, which require robust, wired communication.

Traditional copper PHYs generally have a lower upfront cost for cable and ports, are easy to install and support Power over Ethernet (PoE). They are also a well-established standard that is designed for backwards compatibility and therefore support high levels of interoperability. However, copper is distance limited and can be susceptible to Electromagnetic Interference (EMI), and copper cables have a lower bandwidth than optical PHYs. They are best suited for enterprise and Small and Medium Business (SMB) switches, industrial switches, cellular infrastructure, routers, gateways, FPGA-based systems and other applications.

Optical Ethernet PHYs

We’ve looked at copper, so now let’s look at optical Ethernet PHYs. An optical Ethernet PHY is an integrated circuit or module that implements the physical layer functions for Ethernet communication over optical fiber cables. Where the copper PHY typically interfaces to the cabling via isolation transformers, the optical PHY interfaces to the fiber optic media via a Small Form-Factor, Pluggable (SFP) module, which converts digital data into light signals for transmission over fiber optic cables and vice versa.

Key functions of an optical PHY include:

• Electrical-to-optical conversion: Converts digital electrical signals from the MAC into signals suitable for optical transmission and reception via the SFP module
• Signal encoding/decoding: Encodes data for transmission over fiber and decodes received optical signals
• Auto-negotiation: Determines the optimal speed and duplex mode supported by both ends of the fiber link
• Link-integrity monitoring: Monitors the status of the optical link and reports link status to the MAC
• Physical medium attachment: Interfaces with SFP modules such as SFP, SFP+ and QSFP modules that connect to fiber optic cables

Common applications for optical PHYs are data centers, enterprise networks where the optical PHY is the backbone link between buildings or network segments, telecommunications and industrial networking.

Optical Ethernet PHYs support higher speeds and longer distances, are immune to EMI, consume lower power per lane at high speeds and are smaller in size. However, optical PHYs may have a higher initial cost for cables, and they are more fragile as they have a glass core.

Below is a brief summary of the differences between optical and copper Ethernet PHYs:

Now that we understand the differences between the two Ethernet PHY cables from a 40,000-foot view, let’s take a closer look at optical Ethernet PHYs by exploring Microchip’s newest family of optical Ethernet PHYs.

We recently released a family of next-generation optical PHY transceivers to specifically tackle the demand for advanced networking systems that require connectivity over long distances in harsh environments. These devices support advanced Precision Timing Protocol (PTP), which delivers sub-nanosecond (<1 ns) synchronization accuracy across distributed nodes. This level of timing precision is essential for time-sensitive applications such as industrial automation, telecommunications and robotics.

Our optical PHYs have highly integrated silicon-level security with support for MACsec encryption. This hardware-based implementation protects against network data breaches by encrypting traffic between Ethernet devices. MACsec is designed to thwart common cyberattacks, including man-in-the-middle attacks, Denial-of-Service (DoS), eavesdropping and spoofing, to enable data integrity across the network.

These optical PHYs support 25G and 10G speeds and are designed to meet the stringent requirements of campus-wide networking, server/switch interconnects and small-cell 5G backhaul applications. While copper PHYs (10GBASE-T and 25GBASE-T) are limited to reaching distances of approximately 100 meters over CAT7 cabling and 30 meters over CAT8 respectively, these optical transceivers support link lengths of up to 10 kilometers over single-mode fiber, enabling seamless deployment across geographically dispersed infrastructure.  For shorter runs, such as server-to-server or rack-to-rack connections, these devices also support Direct-Attach Copper (DAC) connections of up to 25 Gbps for distances of up to 5 meters.

The new variants of optical Ethernet PHY transceivers include:

LAN826x supporting up to 10 Gbps

Dual-port:

• LAN8262-V/3HW: 10 Gbps, dual-port, MACsec
• LAN8263-V/3HW: 10 Gbps, dual-port, PTP
• LAN8264-V/3HW: 10 Gbps, dual-port, PTP, MACsec

Quad-port:

• LAN8267-V/3HW: 10 Gbps, quad-port, PTP
• LAN8268-V/3HW: 10 Gbps, quad-port, PTP, MACsec

LAN802x and LAN804x supporting up to 25 Gbps

Dual-port:

• LAN8022-V/3HW: 25 Gbps, dual-port, MACsec
• LAN8023-V/3HW: 25 Gbps, dual-port, PTP
• LAN8024-V/3HW: 25 Gbps, dual-port, PTP, MACsec

Quad-port:

• LAN8042-V/3HW: 25 Gbps, quad-port, MACsec
• LAN8043-V/3HW: 25 Gbps, quad-port, PTP
• LAN8044-V/3HW: 25 Gbps, quad-port, PTP, MACsec

Summary

Copper and optical Ethernet PHYs are valuable network solutions. The one you choose greatly depends on your application and the features that it requires. Microchip has a comprehensive Ethernet portfolio for both traditional copper and optical Ethernet PHYs, and our latest optical PHY family of transceivers delivers reliability and security for engineers building smarter, more secure and scalable networks.

Visit our Ethernet page to learn more.