Isolation between circuit components is often required for security and/or data integrity reasons. For example, isolation protects sensitive circuit components and human-machine interfaces on the system side from dangerous voltage levels present on the field side, where more powerful components such as sensors and actuators are present. Isolation also eliminates common-mode noise or ground loops that affect data acquisition accuracy. While data transfer across the isolation barrier can be achieved with traditional optocouplers or Analog Devices iCoupler devices, the main challenge and common problem is finding a way to transfer power from the non-isolated system side to the isolated field side. This article discusses the technology behind a new approach that addresses this challenge by integrating power isolation and data signal isolation using Analog Devices’ latest iCoupler product.

The international standard for medical safety equipment, IEC 60601, covers the electrical aspects of isolation components and differs from other standards in several ways, including creepage distance and clearance requirements and defibrillation tolerance testing.

The RS-485 communication standard of the Telecommunications Industry Association (TIA) and Electronic Industries Alliance (EIA) was established two decades ago and has been used in a wide variety of applications.

Introduction of optocoupler manufacturers - thyristor driver MOC3082