Smaller, Lower Power 4-20mA Sensor Transmitters for Industrial Equipment

January 23, 2018

Carmelo Morello By: Carmelo Morello
Executive Business Manager, Industrial & Healthcare Business Unit,
Maxim Integrated


In the world of sensor transmitters and programmable logic controllers (PLCs), smaller is definitely better. Smart sensor transmitter technologies are enabling remote monitoring and control of industrial plant factories. However, they’re also driving factory automation equipment to tinier form factors. At the same time, this type of industrial sensor transmitter must also operate with greater power efficiency as well as accuracy.

The analog front-end (AFE) that implements the 4-20mA transmitter plays a critical role in the signal-conditioning chain in sensor transmitters. Designers of these systems not only have tight performance specifications to address, but they also must design for harsh environments. A temperature transmitter could, for example, be placed outside. There, they still must perform reliably when sending data. The AFE would take the digital data from the microprocessor, translate it into the analog domain, and accurately transmit data via a current in the range of 4-20mA to the remote controller.

Automated factory equipment

As factory automation equipment continues to shrink, industrial sensor transmitters must follow suit.

Save Power and Space

Maxim has a new analog IC, the MAX12900 low-power 4mA to 20mA sensor transmitter, that is ideal for today’s industrial equipment requirements. The IC can be used in sensor transmitters that measure parameters such as pressure, temperature, flow, and level. Operating at only 250µA max, the sensor transmitter delivers the low power needed for these applications. Compared to traditional solutions, the MAX12900 delivers:

  • Up to 50% power savings, requiring just 250µA of current maximum
  • High accuracy, at 10ppm/°C voltage reference for up to 3.5x lower drift and 0.01% maximum linearity. Accuracy is particularly important in industries where even a one-degree variation could affect quality of the end product.
  • Up to 20% to 50% smaller solution size. With 10 building blocks integrated into a 5mm x 5mm package, the IC also helps to simplify designs.

With building blocks integrated into the chip, designers no longer need to rely on discrete solutions for their industrial applications. An optimized architecture enables these building blocks to take up less area on the silicon, consume less power, and deliver better accuracy. Another important benefit of the MAX12900 is that it allows designers to more easily implement protection and redundant circuits for an explosion-proof system, so it fits well inside process automation equipment used in the oil, gas, and chemical industries. Systems without such protections could heat up enough to trigger sparks that would cause an explosion in these types of environments.

Learn more about the new sensor transmitter from the MAX12900 data sheet. You can also buy an evaluation kit, the MAX12900EVKIT, to get a closer look at how the sensor transmitter could work in your next industrial design.