A High-Precision Analog Front End Integrated in a 32bit Microcontroller for Industrial Sensing Applications

摘要

This paper describes a microcontroller combining a high-precision AFE and a 32bit controller for industrial sensing applications such as temperature control, recording, weighing, and force sensing. The MCU based on an RXv2 core with DSP and FPU can process complex computations to enable sensor measurements, controls, and communications. By employing the proposed PGA with auto-zeroing technique and chip implementation techniques, the high-precision AFE achieves 29nVrms RMS noise at 7.6 sps, 10 nV/°C offset drift, 0.74 ppm/°C gain drift, which meets the requirements for sensing applications. The MCU enables signals to be measured with better than 0.1% precision without calibration. The temperature measurement system was demonstrated, which indicates sufficient measurement accuracy.