Thermistor_signal_conditioner_for_current_loops

Published:2009/7/24 2:48:00 Author:Jessie | From:SeekIC

Fig. 13-28 This circuit shows a complete 2-wire thermistor temperature-transducer interface with a 4- to 20-mA output. The 4- to 20-mA current-loop control is common in industrial environments. The circuits used to modulate transducer data in a 4- to 20-mA loop must operate well below the 4-mA minimum current. Over a 0 to 100℃ range, accuracy is ±0.3℃ and the circuit is current-loop powered (no external supply is required). Trims shown are for 0℃ and 100℃, and are made by exposing the thermistors to those temperatures. The thermistor datasheets show methods for electrically simulating 0℃ and 100℃, Linear Technology Linear Applications Handbook, 1990 p AN23-5 .



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