Electronic circuit for driving a thermocouple element, temperature sensing device, and method for observing a leakage resistance of the thermocouple element

摘要

Various embodiments include an electronic circuit for driving a thermocouple element comprising: contact electrodes for connecting cold-end electrodes of the thermocouple element; and a measurement circuit to measure a thermo-voltage generated by the thermocouple element. One of the electrodes is connected to a supply voltage and a ground potential over a voltage divider having resistors with pre-defined resistance values such that a common mode voltage between the contact electrode and the ground potential is in a pre-defined range. If a leakage resistance effective between the contact electrode and the ground potential is greater than a pre-defined threshold, a processor compares the common mode voltage to the pre-defined range and generates a calibration value for the measurement circuitry if the common mode voltage is outside the range.