The application provides a four-wire temperature acquisition and self-checking circuit, which comprises a
constant current source generation circuit, a
constant current source detection circuit, a first
operational amplifier conditioning circuit, a second
operational amplifier conditioning circuit, a four-wire temperature acquisition unit and an ADC
data conversion and
communication control unit; the ADC
data conversion and
communication control unit comprises an ADC conversion
chip A3 for outputting and inputting a reference
voltage VREF; the
constant current I_TEMP output by the
constant current source generation circuit flows through the sampling
resistor R10 and the four-wire temperature acquisition unit, and the
voltage generated across the sampling
resistor R10 is input to the
constant current source detection circuit to output the
voltage TEMP_V to the ADC conversion
chip A3; when the I_TEMP flows through the four-wire temperature measuring element RT in the four-wire temperature acquisition unit, the voltage generated across the four-wire temperature measuring element RT is input to the first
operational amplifier conditioning circuit and the second operational
amplifier conditioning circuit respectively, and then the stable voltages TEMP_VA and TEMP_VB are output to the ADC conversion
chip A3 respectively. The application can improve the temperature measuring precision and the accuracy of detecting the voltages of the circuits, and ensure the normal operation of the
system in the case of one-side fault.