High-Precision Mixed-Signal Sensor Interface for a Wide Temperature Range [0° – 300°C]

Sensor interfacing is a crucial component for today's systems in many application domains. Especially in automotive and manufacturing fields, high temperatures are encountered. For extracting the typically small sensor signals, an interface near the sensor is needed to provide high accuracy and robustness. This results in challenges in circuit design and architecture to avoid temperature-related nonideal effects. In this contribution, we present a novel system architecture for a Wheatstone bridge interfacing system. By encoding the sensor signal in time domain and augmenting the system with additional observations, we present a robust and precise sensor interface operating at up to 300°C without breaking accuracy or functional requirements because of high-temperature effects. We present a realization of this concept proven to be accurate within ±1.3% full scale over the full temperature range.