SLYT847 May   2024 DAC161S997 , DAC8551 , TVS3301

 

  1.   1
  2. 1 Introduction
  3. 2 4mA to 20mA transmitter basics
  4. 3 4mA to 20mA transmitter design aspects
  5. 4 Design performance metrics
  6. 5 Transmitter circuit implementations
  7. 6 Dedicated loop converter
  8. 7 Loop transmitter device
  9. 8 MCU integrated DAC
  10. 9 PWM-based DAC
  11. 10Stand-alone low power DAC
  12. 11Implementations Comparison
  13. 12Conclusion
  14. 13Related websites

1 Introduction

In any process control system, sensor transmitters collate data from pressure and temperature to flow and level, and relay this information to the programmable logic controller (PLC) or distributed control system.

These transmitters depend on the 4mA to 20mA signal to transmit data to the controller. Despite the emergence of standards such as IO-Link and Profibus, 4mA to 20mA offers resiliency over long distances, reliability, immunity to noise, and universal compatibility with every PLC system.

In this article, I will provide an overview of the 4mA to 20mA transmitter structure, its operating principles, and design alternatives for implementing this transmitter type using catalog semiconductor products.