NAMUR PLC Digital input with fault protection and diagnostics reference design


Design files


The NAMUR proximity sensor is widely used in industrial control when a special requirement on maximum energy is to be fulfilled by the sensor. This in turn dictates special requirements on the PLC digital input designed to interface with such sensor with regard to accuracy, and reliability. This reference design is a full front-end of a digital input compatible with NAMUR sensors. The design demonstrates achieving reliability through redundancy, fault protection, and extensive diagnostic features in a compact footprint.

  • 1.6-mA threshold, 0.4-mA hysteresis
  • 0.2-mA open circuit, 6-mA short-circuit threshold
  • 8.2-V open-circuit voltage, 8.2-mA short-circuit current
  • Extensive diagnostics
  • Fault protection
  • Power and data isolation
  • Redundant components for higher reliability
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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.

TIDUEL4.PDF (1014 K)

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


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

TIDCF28.ZIP (388 K)

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


PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

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Design tools & simulation

Simulation model

TIDA-010044 Simulation Files — TIDM053.ZIP (75 K)

Technical documentation

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Type Title Date
* Design guide NAMUR PLC Digital Input With Fault Protection and Diagnostics Reference Design Dec. 10, 2018

Related design resources

Design tools & simulation

TINA-TI SPICE-based analog simulation program

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