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

A temperature sensing device comprising:

• a thermocouple element;
• contact electrodes for connecting cold-end electrodes of the thermocouple element;
• a measurement circuit to measure a thermo-voltage generated by the thermocouple element between the contact electrodes as a function of a temperature difference between the cold-end electrodes and a hot-end side of the thermocouple element;
• wherein one of the contact electrodes is connected to a supply voltage and to a ground potential of the electronic circuit 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;
• and
• a processor to compare the common mode voltage to the pre-defined range and to generate a calibration value for the measurement circuitry if the common mode voltage is outside said pre-defined range.

A method for determining a temperature related signal using a thermocouple element and observing a leakage resistance of the thermocouple element, the method comprising:

• measuring a thermo-voltage generated by the thermocouple element between contact electrodes as a function of a temperature difference between the cold-end electrodes and a hot-end side of the thermocouple element;
• wherein one of the contact electrodes is connected to a supply voltage and a ground potential of an electronic circuit over a voltage divider having resistors with pre-defined resistance values;
• generating a common mode voltage with the voltage divider between the contact electrode and the ground potential, wherein the common mode voltage is in a pre-defined range;
• if a leakage resistance effective between the contact electrode and the ground potential exceeds a pre-defined threshold, comparing the common mode voltage to the pre-defined range;
• and
• if the common mode voltage is outside said pre-defined range, generating a calibration value for calibrating the measurement circuit.