The following circuit diagram is designed by Elana Lian and Chau Tran from Analog Device. The circuit includes T1, a low-cost AD590 temperature sensor; IC1, an AD8541 rail-to-rail amplifier; four resistors; a trimming potentiometer; and an ADC. The AD590 is a 2-terminal integrated circuit temperature transducer that produces an output current proportional to absolute temperature. The AD590 provides an output current proportional to absolute temperature (1 µA/K). In this application, the circuit offsets and scales the output to provide a full-scale range of 0 to 5V with a scale factor of 50 mV/°C over the chosen temperature range of 0°C—the freezing point of water—to 100°C, the boiling point of water.
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