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Gigaspeed Isolated LVDS: Unlocking New Possibilities

Digital isolation technology, including isolated low voltage differential signaling (LVDS), has an important function in diverse end applications, such as isolated video and imaging for digital healthcare, channel-to-channel isolation for instrumentation, and isolation of the data planes in industrial applications.

Digital isolation acts as an invisible force field that protects people and equipment from harm by safeguarding a design against electromagnetic interference (EMI). High-speed, isolated LVDS leverages this principle to enable robust and reliable system communication.

It can be daunting to find a device that meets all your isolation needs, especially where safety to the person and equipment are crucial, robust data capture is required, and signal integrity is a must. The Gigaspeed Isolation blog series will focus on applications that require digital isolation technology and demand signal integrity in the gigabits-per-second (Gbps) realm. We will cover…

  • Selection of an isolation device that meets the requirements of your application and an isolated power solution to go with it.
  • A worked example using ADI simulation tools to support and expedite the design phase.
  • Isolation for high-speed video applications, with a focus on HDMI for digital healthcare applications.
  • Extending the capability of Industrial PC interface with the Isolation of high speed interfaces such as PCIe
  • Using isolated LVDS iCoupler technology from Analog Devices, Inc. (ADI) with different architectures.

 

Low Voltage Differential Signaling (LVDS)

LVDS is a low-power communication interface that has been adopted in, for example, high-speed backplane cabled applications, board-to-board data transmission, or applications that require clock distribution.

LVDS is a technical standard governing the transmission of signals through a twisted pair cable with a near-zero voltage differential between the wires. Because the wires are twisted together, they’re subjected to nearly identical EMI, and those identical signals can easily be discarded as noise.

In short, LVDS uses differential signals to transmit information and weed out interference. It offers advantages in power consumption and electromagnetic compatibility (EMC). It’s even fast—very fast—but is it gigaspeed fast?

 Schematic of basic LVDS Tx and Rx Circuit

Figure1. Schematic of basic LVDS Tx and Rx Circuit Understanding LVDS Fail-Safe Circuits | Analog Devices
 

What Is Gigaspeed?

Ultra-fast gigaspeed technology can unlock protocol support given the low power and low voltage levels applicable for leading-edge video, display, and camera sensor innovations. High-definition displays and high-speed image capture help enable vehicle autonomy and safety features, autonomous mobile robots, and smarter, safer surgical equipment, just to give a few examples.

Gigaspeed 1,000 Mbps

But it’s no small feat to move this high-stakes data from Point A to Point B—say, from the tip of an endoscope all the way to a surgeon’s digital display, or from a vehicle’s camera sensors to its central control unit where safety decisions are made and carried out.

Maybe you’re designing a Gbps AFE, where channel-to-channel isolation is needed and high working voltages (400 V, 800 V) are a must. Or maybe you’re working with interface protocols such as HMDI and PCIe, which require speeds in the Gbps, signal integrity, and guaranteed signal robustness. Whatever your design, if it needs to move 1,000 Mbps or more, a gigaspeed solution can help.
 

Gigaspeed Isolated LVDS: The Best of Both Worlds

 circuit diagram of ADN4621 Dual channel 2.5GBbps LVDS Isolator

Figure 2: ADN4621 Dual channel 2.5GBbps LVDS Isolator

ADI’s Gigaspeed Isolated LVDS family of devices offer versatility when designing isolation for gigaspeed applications. They are uniquely capable of operating at 2.5Gbps for individual channels, or with all channels combined can support speeds up to 10Gbps. Below are some highlights of the ADN462x solution family.

  • High speed operation
  • Low power consumption
  • Low jitter
  • TIA/EIA-644-A compliant for signal levels
  • IEC6100-4-2 compliant for electrostatic discharge (ESD) operation

Whether your priority is to manage creepage and clearance, to support functional/basic isolation, or to provide reinforced isolation, there are various package options to choose from on the Gigaspeed Isolated LVDS shelf. More details on ADIs iCoupler Isolation technology portfolio.
 

Up Next: Choosing an Isolated Power Solution

Before starting out with a design, it’s key to have a clear definition of your requirements. Determining the right level of isolation is only the first step. A robust design must also optimize power, end solution size, and of course, signal integrity to achieve the best performance.

The second part of this blog series will walk you through the selection of an isolated power solution for your design. We will work through the key performance vectors associated with the ADN462x devices, highlighting the value of using LTSPICE to determine the performance for your design.

 

Additional Resources