ADM2582E - FAQ

What is transformer isolation?

Transformer isolation employs transformer coils to transmit information across an isolation barrier. Changes in current through the transformer winding on one side of the isolation barrier induce a corresponding current on the transformer winding on the other side of the isolation barrier. Transformer-based methods have been commonly used in applications involving AC signals (Ethernet, for example) that are well suited for transformer coupling. Transformer isolation has advantages in systems with high data rates, and it can also be used to provided an isolated power supply; however, transformers have typically been bulkier than alternative solutions.

iCoupler technology (see below) is a form of transformer isolation that employs micro-transformer coils to address the size and integration disadvantages of discrete transformer solutions.

With which regulatory standards do iCoupler products comply?

iCoupler products typically carry at least a 2.5 kVRMS UL rating and a 400 VRMS working voltage approval from CSA and UL.

The approvals and details for each specific product are summarized in the table available at www.analog.com/iCouplerSafety

Are iCoupler products Pb-free?

All iCoupler products are offered with Pb-free versions.

What are the benefits of iCoupler technology?

iCoupler technology provides benefits in five key areas:

Integration benefits are provided by the ability to readily combine iCoupler channels with other semiconductor functions or to combine multiple iCoupler channels in a common package thereby reducing size and cost relative to optocoupler implementations. Performance benefits are provided in the form of increased timing accuracy, transient immunity, and data rates relative to optocoupler components. Power consumption benefits are provided in the form of 10-to-50 times lower power consumption as well as the accompanying reduction in thermal dissipation.

Ease-of-use benefits are provided by the elimination of many of the difficulties presented by optocoupler technology as well as the addition of new features that facilitate the use of iCoupler isolators in new designs. Optocoupler problem areas that iCouplers eliminate include their characteristic of widely-varying current transfer ratios, their LED wear-out phenomenon and the design burdens this imposes, and their need (in most optocouplers) to drive their input with high current to turn on the LED. Additional ease-of-use features that iCouplers provide include the ability to operate at reduced supply voltages, the ability to translate an input signal of one voltage into an output signal of a different voltage, the use of voltage-based digital interfaces, and the ability to operate over a wide temperature range.

Lastly, reliability benefits are achieved by the elimination of the LEDs contained within optocouplers. By using only standard CMOS process technology, iCoupler devices provide the same lifetime characteristics as other standard CMOS products.

Does Analog Devices provide other products that employ iCoupler technology?

A significant benefit of iCoupler technology is its ability to integrate isolation in a wide range of products. Integrating iCoupler isolation with other products simplifies designs, reduces the bill-of-materials, lowers cost, reduces size and increases reliability.

The ADM2483, ADM2485, ADM2486 and ADM2490E are RS-485 transceivers that employ iCoupler technology. Likewise, the AD7400 and AD7401 are isolated ΣΔ analog-to-digital converters. In the future, Analog Devices will release additional products integrated isolation via iCoupler technology.

How do I learn about new iCoupler products?

Please visit the Analog Devices website at www.analog.com/icoupler for the most up-to-date information on new products. You may also contact your local Analog Devices Sales representative. A quarterly newsletter, "Analog Devices' Digital Isolation Update," is also available. The newsletter includes new product announcements as well as news, application tips and technical information about the iCoupler technology. Please refer to www.analog.com/Subscriptions to learn how to subscribe to the "Analog Devices' Digital Isolation Update."

How do iCoupler products differ from interface products?

iCoupler isolation products are a subset of traditional interface products. Typically, a given iCoupler product may be suitable for a wide array of applications, whereas interface-specific products are limited in scope (e.g., RS-232 or RS-485 transceivers). In addition, interface-specific products may not require isolation; however, it is common that such interfaces also require some level of isolation. Analog Devices offers a variety of interface products, some of which integrate iCoupler technology for a fully integrated solution (see below).