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 a high-accuracy and robustness.

This results in challenges for circuit design and architecture to avoid temperature related non-ideal 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 obseravtions, we present a robust and precise sensor interface operating at up to 300°C. We present a realization of this concept proven to be accurate within ±1.3%FS over the full temperature range.