Temperature sensor circuit

1. A temperature sensor circuit ( 1 ) for measuring a temperature, the temperature sensor circuit comprising:

a measurement resistor ( 2 ) and a controllable voltage source ( 3 ) or current source ( 3 ) which is connected to the measurement resistor ( 2 ) and configured to apply an input voltage to the measurement resistor ( 2 ), wherein the input voltage can be adjusted continuously using the controllable voltage source ( 3 ) or current source ( 3 );

wherein a first connection ( 6 ) for reducing a first measurement voltage signal is at a first end ( 5 ) of the measurement resistor ( 2 );

wherein a second connection ( 8 ) for reducing a second measurement voltage signal is at a second end ( 7 ) of the measurement resistor ( 2 );

wherein an analog/digital converter ( 9 ) is connected the first connection and the second connection for reducing a differential measurement voltage based on the first and second measurement voltage signals; and

wherein the analog/digital converter ( 9 ) converts the differential measurement voltage into a digital voltage signal.

2. The temperature sensor circuit ( 1 ) as claimed in claim 1 , further comprising a voltage divider resistor ( 4 ), with which the measurement resistor ( 2 ) is connected in series.

3. The temperature sensor circuit ( 1 ) as claimed in claim 1 , wherein a current sensor ( 10 ) is connected in series with the measurement resistor ( 2 ) in order to measure an electrical current flowing through the measurement resistor ( 2 ).

4. The temperature sensor circuit ( 1 ) as claimed in claim 1 , having an evaluation circuit ( 11 ) which is configured to regulate the controllable voltage source ( 3 ) on the basis of an input variable from the temperature sensor circuit ( 1 ) in order to adapt the input voltage to the input variable.

5. The temperature sensor circuit ( 1 ) as claimed in claim 1 , wherein the controllable voltage source ( 3 ) or current source ( 3 ) has a PWM module ( 12 ) which is connected to a damping resistor ( 13 ) and a capacitor ( 14 ) in order to generate the input voltage from a constant supply voltage, wherein the input voltage is regulated by specifying a pulse width for the PWM module ( 12 ).

6. A method for carrying out a temperature measurement using a temperature sensor circuit ( 1 ) having a measurement resistor ( 2 ) and a controllable voltage source ( 3 ) or current source ( 3 ) which is connected to the measurement resistor ( 2 ) and configured to apply an input voltage to the measurement resistor ( 2 ), wherein the input voltage is adjusted using the controllable voltage source ( 3 ) or current source ( 3 ), the method comprising steps of:

a) providing a measurement current ( 15 ) which flows through the measurement resistor ( 2 ) for the temperature measurement,

b) providing an increased measurement current ( 19 ) which flows through the measurement resistor ( 2 ) for the temperature measurement in at least one limited interval of time ( 20 ), and

c) providing a measurement signal of the temperature measurement, wherein an accuracy of the temperature measurement is increased during the limited interval of time ( 20 ) from step b);

d) detecting sensor heating ( 17 ) as a result of the measurement current ( 15 ), and

e) decreasing the length of the limited interval of time to reduce the sensor heating ( 17 ) on the basis of the heating detected in step d).

7. The method as claimed in claim 6 , further comprising steps of:

e) regulating at least one of the following parameters on the basis of the heating detected in step d):

intensity of the increased measurement current ( 19 ) in step b),

intensity of the measurement current ( 15 ) in step a), and

repetition rate of step b).

8. A non-transitory, computer-readable media containing program instructions that when executed by a computer cause the computer to control a temperature sensor circuit having ( 1 ) a measurement resistor ( 2 ) and a controllable voltage source ( 3 ) or current source ( 3 ) which is connected to the measurement resistor ( 2 ) and configured to apply an input voltage to the measurement resistor ( 2 ), wherein the input voltage is adjusted using the controllable voltage source ( 3 ) or current source ( 3 ), to:

a) provide a measurement current ( 15 ) which flows through the measurement resistor ( 2 ) for the temperature measurement,

b) provide an increased measurement current ( 19 ) which flows through the measurement resistor ( 2 ) for the temperature measurement in at least one limited interval of time ( 20 ), and

c) provide a measurement signal of the temperature measurement, wherein an accuracy of the temperature measurement is increased during the limited interval of time ( 20 ) from step b);

d) detect sensor heating ( 17 ) as a result of the measurement current ( 15 ), and

e) decrease the length of the limited interval of time to reduce the sensor heating ( 17 ) on the basis of the heating detected in step d).