Title :
An integrated 4-20 mA two-wire transmitter with intrinsic temperature sensing capability
Author :
Filho, Carlos A dos Reis
Author_Institution :
Dept. of Electr. Eng., Delft Univ. of Technol., Netherlands
fDate :
8/1/1989 12:00:00 AM
Abstract :
An integrated two-wire transmitter which converts signals from temperature sensors, resistance temperature detectors (RTDs), and thermocouples into an industrial standard 4-20 mA output is discussed. This transmitter is unique in that it is a silicon temperature sensor with a standard output which also allows compensation for the cold junction of thermocouples. The device is p-i-n programmable to perform different functions of signal conditioning and has been implemented on a standard bipolar linear IC process. Measured samples of an experimental chip configured as an RTD-signal conditioner have shown an accuracy of 0.1% and a nonlinearity of 0.02%. As a temperature sensor over the range 0.85°C, the TWT has been accurate within ±1°C
Keywords :
bipolar integrated circuits; electric sensing devices; linear integrated circuits; temperature measurement; thermocouples; 0 to 85 degC; 4 to 20 mA; TWT; accuracy; bipolar linear IC process; cold junction; industrial standard; nonlinearity; p-i-n programmable; resistance temperature detectors; signal conditioning; temperature sensing capability; temperature sensors; thermocouples; two-wire transmitter; Detectors; Feedback loop; Sensor phenomena and characterization; Silicon; Temperature sensors; Thermal resistance; Thermal sensors; Thermistors; Transmitters; Voltage;
Journal_Title :
Solid-State Circuits, IEEE Journal of
