Apparatus, Sensor Circuit, and Method for Operating an Apparatus or a Sensor Circuit

• US 20110270553A1
• Filed: 04/30/2010
• Published: 11/03/2011
• Est. Priority Date: 04/30/2010
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Kolle, Christian, Motz, Mario, Ausserlechner, Udo
• Granted Patent: US 8,442,787 B2
• Time in Patent Office: Days
• US Class Current: 702/64
• CPC Class Codes: G01D 3/036 on measuring arrangements themselves
• CPC Class Codes: G01D 3/0365 the undesired influence being measured using a separate sensor, which produces an influence related signal
• CPC Class Codes: G01N 27/72 by investigating magnetic variables
• CPC Class Codes: G01R 15/181 using coils without a magnetic core, e.g. Rogowski coils
• CPC Class Codes: G01R 15/202 using Hall-effect devices Hall elements in arrangements for measuring electrical power G01R21/08
• CPC Class Codes: G01R 22/066 Arrangements for avoiding or indicating fraudulent use
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844

Abstract

An apparatus is described, including: a signal processing circuit adapted to process an input signal to obtain an output signal; a sensor element for sensing a predetermined physical quantity, wherein the sensor element is adapted to generate a sensor signal in response to the predetermined physical quantity; wherein the signal processing unit is adapted to process the input signal to obtain the output signal depending on the sensor signal; and wherein the apparatus further comprises an evaluation circuit adapted to evaluate the sensor signal and to generate an indication signal indicating an abnormal operating condition in case the sensor signal does not fulfill a predetermined normal operation criterion.

Claims

1. An apparatus, comprising:

a signal processing circuit adapted to process an input signal to obtain an output signal;

a sensor element adapted to sense a predetermined physical quantity, wherein the sensor element is adapted to generate a sensor signal in response to the predetermined physical quantity;

wherein the signal processing unit is adapted to process the input signal to obtain the output signal based on the sensor signal; and

an evaluation circuit adapted to evaluate the sensor signal and derive from the sensor signal an indication signal indicating an abnormal operating condition in case the sensor signal does not satisfy a predetermined normal operation criterion.

2. The apparatus according to claim 1, wherein the apparatus further comprises an output port and is adapted to output the indication signal via the output port.

3. The apparatus according to claim 1, wherein the apparatus is adapted to output the output signal via the same output port as the indication signal, or comprises a further output port and is adapted to output the output signal via the further output port.

4. The apparatus according to claim 1, wherein the apparatus comprises a package and comprises an output port to output the indication signal, and wherein the sensor element, the signal processing unit and the evaluation circuit are encapsulated in the package by an encapsulating material.

5. The apparatus according to claim 1, wherein the predetermined physical quantity is a temperature and the sensor element comprises a temperature sensor element, or wherein the predetermined physical quantity is a mechanical stress and the sensor element comprises a mechanical stress sensor element.

6. The apparatus according to claim 5, wherein the sensor element is located at a first position and the apparatus comprises a further sensor element at a second location of the apparatus, wherein the sensor element is adapted to generate the sensor signal depending on the predetermined physical quantity at the first position, wherein the further sensor element is adapted to generate a further sensor signal depending on the predetermined physical quantity at the second position, wherein the predetermined normal operation criterion defines a maximum magnitude of a difference between the sensor signal and the further sensor signal, and wherein the evaluation circuit is adapted to evaluate a difference between the sensor signal and the further sensor signal and generate the indication signal in case a magnitude of the difference is higher than a maximum magnitude of the difference between the sensor signal and the further sensor signal.

7. The apparatus according to claim 1, wherein the apparatus comprises a sensor circuit for measuring a primary physical quantity and further comprises:

a primary sensor element adapted to generate a primary sensor signal as the input signal in response to the primary physical quantity; and

wherein the signal processing unit is adapted to process the primary sensor signal based on the input signal to obtain a primary measurement signal as the output signal, wherein the primary measurement signal represents a property of the primary physical quantity.

8. The apparatus according to claim 7, wherein the sensor element is a secondary sensor element, and wherein the predetermined physical quantity comprises a secondary physical quantity, which is of a different type of a physical quantity than the primary physical quantity.

9. The apparatus according to claim 8, wherein the signal processing unit is adapted to compensate a drift of a value of the primary sensor signal with regard to the primary measurement signal caused by a variation of the predetermined physical quantity.

10. The apparatus according to claim 7, wherein the predetermined normal operation criterion defines a maximum magnitude for a change of the sensor signal over time, and wherein the evaluation circuit is adapted to compare a magnitude of a change of the sensor signal over time with the maximum magnitude for a change of the sensor signal and to generate the indication signal in case the magnitude of the change of the sensor signal over time is higher than the maximum magnitude for a change of the sensor signal.

11. The apparatus according to claim 7, wherein the predetermined physical quantity corresponds to the primary physical quantity, wherein the primary sensor element comprises a first primary sensor element adapted to produce the primary sensor signal as a first primary sensor signal in response to the primary physical quantity at a first position, and the sensor element comprises a second primary sensor element adapted to generate a second primary sensor signal as sensor signal in response to the primary physical quantity at a second position,

wherein the signal processing circuit is adapted to process the first and second primary sensor signals according to a first algorithm to obtain the measurement signal;

and

wherein the evaluation circuit is adapted to process the first and the second primary sensor signals according to a second algorithm, which is different from the first algorithm, and generate the indication signal in case the result of the second algorithm does not fulfill a predetermined normal operation criterion, or

wherein the evaluation circuit is adapted to process the second primary sensor signal and the measurement signal according to a third algorithm, which is different from the first algorithm, and generate the indication signal in case the result of the third algorithm does not fulfill a predetermined normal operation criterion.

12. The apparatus according to claim 11, wherein the first algorithm is a differential measurement algorithm and comprises subtracting the first primary sensor signal or a multiple thereof from the second primary sensor signal or a multiple thereof, or vice versa.

13. The apparatus according to claim 12, wherein the second algorithm comprises adding the first primary sensor signal or a multiple thereof and the second primary sensor signal or a multiple thereof to obtain a sum value, and

wherein the predetermined normal operation criterion defines a static maximum value, wherein the evaluation circuit is adapted to generate the indication signal in case the sum value or a value derived therefrom is larger than the static maximum value, or

wherein the predetermined normal operation criterion defines a static maximum magnitude, wherein the evaluation circuit is adapted to generate the indication signal in case a magnitude of the sum value or of a value derived therefrom is larger than the static maximum magnitude, or

wherein the predetermined normal operation criterion defines a dynamic maximum value based on at least the first primary sensor signal or the measurement signal, wherein the evaluation circuit is adapted to generate the indication signal in case the sum value or a value derived therefrom is larger than the dynamic maximum value, or

wherein the predetermined normal operation criterion defines a dynamic maximum magnitude based on at least the first primary sensor signal or the measurement signal, wherein the evaluation circuit is adapted to generate the indication signal in case a magnitude of the sum value or a value derived therefrom is larger than the dynamic maximum magnitude.

14. The apparatus according to claim 11, wherein the second algorithm comprises determining a ratio of the first primary sensor signal over the second primary sensor signal, or vice versa, and wherein the predetermined normal operation criterion defines a maximum ratio, and wherein the evaluation circuit is adapted to generate the indication signal in case the ratio, a magnitude of the ratio or another value derived from the ratio is larger than the maximum ratio, or

wherein the third algorithm comprises determining a ratio of the second primary sensor signal over the measurement signal, or vice versa, and wherein the predetermined normal operation criterion defines a maximum ratio, and wherein the evaluation circuit is adapted to generate the indication signal in case the ratio, a magnitude of the ratio or another value derived from the ratio is larger than the maximum ratio.

15. Apparatus according to claim 11, wherein the second primary sensor element is adapted to generate a plurality of sensor signals over time, wherein the predetermined normal operation criterion defines an maximum average value of the second primary sensor signal for a predetermined duration, and wherein the evaluation circuit is adapted to determine an average value of the second primary sensor signal for the predetermined duration and to generate the indication signal in case the average value of the second primary sensor signal is higher than the maximum average value of the sensor signal, and/or

wherein the predetermined normal operation criterion defines an minimum average value of the second primary sensor signal for a predetermined duration, and wherein the evaluation circuit is adapted to determine an average value of the second primary sensor signal for the predetermined duration and to generate the indication signal in case the average value of the second primary sensor signal is smaller than the minimum average value of the sensor signal.

16. The apparatus according to claim 15, wherein the predetermined duration corresponds to a period of a wanted primary physical quantity at normal operation conditions.

17. The apparatus according to claim 11, wherein the sensor circuit is a magnetic field current sensor circuit comprising a primary conductor and a first and a second magnetic field sensor element as first and second primary sensor element, wherein the magnetic field produced by a current to be measured flowing through the primary conductor is different on both sensor elements,

wherein the first magnetic field sensor element and the second magnetic field sensor element are arranged such and the signal processing circuit is adapted to process the first and second sensor signal to obtain the measurement signal such that unwanted homogeneous magnetic field parts of the first and second sensor signal caused by other sources than the current to be measured cancel each other or at least reduce each other, and

wherein the evaluation circuit is adapted to evaluate the second primary sensor signal using the first sensor signal and/or the measurement signal.

18. The apparatus according to claim 7, wherein the primary sensor element and the sensor element are integrated into a single semiconductor die, or wherein the primary sensor element, the sensor element, the signal processing unit and the evaluation circuit are integrated into a single semiconductor die.

19. A current sensor circuit comprising:

a signal processing unit adapted to process at least one sensor signal of a plurality of sensor signals generated by at least one magnetic field sensor element to obtain a measurement signal; and

an evaluation circuit adapted to evaluate the at least one sensor signal of the plurality of sensor signals using at least one other sensor signal or the measurement signal to derive an indication signal indicating an abnormal operation condition in case the at least one sensor signal does not fulfill a predetermined normal operation criterion,

wherein the predetermined normal operation criterion is derived from a predetermined temporal or spatial relation between a value of the at least one sensor signal and a value of the at least one other sensor signal of the plurality of sensor signals during a normal operation condition.

20. The current sensor circuit according to claim 19, further comprising a primary conductor and a first and a second magnetic field sensor element as first and second primary sensor elements, respectively, wherein the magnetic field produced by a current to be measured flowing through the primary conductor is different on both sensor elements, wherein the at least one sensor signal is produced by the first magnetic field sensor element and the at least one other sensor signal is produced by the second magnetic field sensor element,

wherein the first magnetic field sensor element and the second magnetic field sensor element are arranged on opposite sides of the primary conductor, and wherein the signal processing circuit is adapted to process the at least one sensor signal and the at least one other sensor signal to obtain the measurement signal according to a differential measurement principle.

21. The current sensor circuit according to claim 20, further comprising a third magnetic field sensor element as a third primary sensor element adapted to produce a further sensor signal, wherein the first, second and third magnetic field sensor elements are not arranged on a straight line, and wherein the signal processing circuit is adapted to process the at least one sensor signal, the at least one other sensor signal and the further sensor signal to obtain the measurement signal according to a differential measurement principle.

22. A method for operating an apparatus comprising a sensor element for sensing a predetermined physical quantity, the method comprising:

sensing the predetermined physical quantity by the sensor element and generating a sensor signal in response to the sensed predetermined physical quantity;

processing an input signal to obtain an output signal based on the sensor signal; and

evaluating the sensor signal and generating an indication signal indicating an abnormal operating condition in case the sensor signal does not fulfill a predetermined normal operation criterion.

23. A method for operating a sensor circuit comprising a first primary sensor element and a second primary sensor element, the method comprising:

generating a first primary sensor signal by the first primary sensor element in response to a first primary physical quantity comprising a first wanted part or a first unwanted ambient part; and

generating a second primary sensor signal by the second primary sensor element in response to a second primary physical quantity comprising a second wanted part or a second unwanted ambient part, wherein the second primary physical quantity is of a same type as the first primary physical quantity;

processing the first primary sensor signal and the second primary sensor signal according to a first algorithm to obtain a measurement signal; and

evaluating the first primary sensor signal and the second primary sensor signal according to a second algorithm that is different than the first algorithm and generating an indication signal indicating an abnormal operating condition in case the result of the second algorithm sensor signal does not fulfill a predetermined normal operation criterion, or

evaluating the second primary sensor signal and the measurement signal according to a third algorithm, which is different from the first algorithm, and generating the indication signal in case the result of the third algorithm does not fulfill a predetermined normal operation criterion.

24. A computer program having a program code for performing a method for operating an apparatus comprising a sensor element for sensing a predetermined physical condition, the method comprising:

sensing the predetermined physical quantity by the sensor element and generating a sensor signal in response to the predetermined physical quantity;

processing an input signal to obtain an output signal based on the sensor signal; and

evaluating the sensor signal and generating an indication signal indicating an abnormal operating condition in case the sensor signal does not fulfill a predetermined normal operation criterion.