A novel BIMOS signal processor for Pt 100 temperature sensors with microcontroller interfacing

Abstract This paper describes a new high-performance temperature-measurement system for the temperature range − 200 °C to 850 °C, based on the use of Pt 100 temperature-dependent resistors. The output signal is a time-multiplexed frequency-modulated voltage, which can be processed by microcontrollers without any additional interface circuitry. The system, which is designed for implementation on a single BIMOS chip, does not need calibration or range switching. The power supply voltage amounts to only 5 V. The accuracy of the electronic circuit is better than that specified in the IEC 751 standard for the Pt 100 itself.