Broken Wire Detection Using An Optical Switch Reference Design


Design files


This reference design shows a compact implementation of 16 isolated digital input channels using TI's ISO121x devices. The design is split into two groups of eight channels each. A broken wire detection can be executed using only one additional optical switch for each channel or two optical switches and one additional capacitor for each group. For this functionality no secondary side supply is needed, which gives a unique benefit to digital input modules using the ISO121x family.

  • 16 digital input channels with up to ±60-V input voltage tolerance
  • Broken wire detection for with only one additional component
  • Works with primary supply only, no isolated power supply needed
  • LaunchPad™ header for quick and easy evaluation
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.


Reference design overview and verified performance test data


Detailed schematic diagram for design layout and components


Complete listing of design components, reference designators, and manufacturers/part numbers


Detailed overview of design layout for component placement

TIDRVI1.ZIP (1278 K)

Files used for 3D models or 2D drawings of IC components


Design file that contains information on physical board layer of design PCB

TIDRVI0.PDF (1613 K)

PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

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Isolated digital inputs

ISO1211Single-channel Isolated 24-V to 60-V digital input receiver for digital input modules

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Isolated digital inputs

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Shift registers

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Technical documentation

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Type Title Date
* Design guide Broken Wire Detection Using an Optical Switch Reference Design Jan. 26, 2018

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