CN-0233 Circuit Note is a reference circuit from Analog Devices that aims to help solve today's analog, mixed-signal, and RF design challenges. The circuit has been designed and tested by engineers for quick and easy system integration.
The document presents a reference design for industrial and instrumentation systems requiring multichannel isolation. The circuit integrates digital isolation, PWM-controlled power regulation, and feedback isolation to control outputs ranging from 4 mA to 20 mA or up to 15 V.
Key components include the ADuM347x family of quad-channel digital isolators with integrated transformer drivers and the AD5422 16-bit voltage and current output DAC. The design utilizes external transformers for power transfer across the isolation barrier, eliminating the need for separate isolated DC-to-DC converters.
The ADuM347x isolators are available with a maximum data rate of 25 Mbps for C grade.