1 Introduction

Field transmitters are essential devices used in various industries and applications to measure, monitor, and transmit data from sensors located in remote or challenging environments. The importance of these sensors lies in the ability to facilitate accurate and real-time data transmissions, which is crucial for process control and safety.

Field transmitters are located in remote or hard-to-reach areas, such as oil rigs, pipelines, chemical plants, or environmental monitoring sites. Field transmitters allow for monitoring and control of processes and systems without the need for frequent manual intervention.

For real-time data transmission, field transmitters offer different analog and digital interfaces. Typical analog output interfaces consist of a two-wire, loop-powered, 4-20 mA current output or radiometric voltage output. Notably, digital interfaces like IO-Link, SPE, HART and APL are currently available.

Safety approvals are very common in industries like chemical, power generation, and oil and gas, but also in mobile applications. Safety approvals help prevent accidents, protect the environment, and save human lives with high levels of quality and reliability function.

Pressure sensors represent one of the highest volumes in the market. The price target for the active component BOM is very challenging because of this high volume. The sensors are mounted near the process, or in harsh environments, and require wide operation temperature ranges between -40°C up to 125°C. Since pressure changes are dynamic, settling times lower than 1 ms are standard .

A high-gain and low-noise AFE is required to achieve accuracy in the range of 0.01% - 0.1% because the strain gauge (Wheatstone bridge) typically used in a pressure sensor only delivers small voltages in the range of lower than 5 mV full-scale. Typical sensor housings incorporate the form factor of an M17 or M21 screw, which limits the possible PCB size. Achieving a low-power, high-gain front end within reasonable area and cost is challenging and requires a reasonable level of integration.

The MSPM0 MCU is a great design for these challenges with a wealth of integrated flexible analog resources. Leveraging the internal peripherals, such as ADCs, chopper-stabilized operational amplifiers, and DACs can help solve these technical challenges. Section 3 introduces how an MSPM0-based front end can overcome the aforementioned challenges.