Detection of dependent failures

• US 10,229,805 B2
• Filed: 08/18/2016
• Issued: 03/12/2019
• Est. Priority Date: 02/19/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Zettler, Thomas, Herfurth, Kirk
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US15/240,544
• Publication Number:
  US 20160365213A1
• Time in Patent Office: 936 Days
• Field of Search: 307116
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01L 1/00 Measuring force or stress, in general measuring force due to impact G01L5/00
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: G01R 29/0878 Sensors; antennas; probes; detectors wave guide measuring sections G01R1/24
• 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
• CPC Class Codes: G01T 1/00 Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation G01T3/00, G01T5/00 take precedence
• CPC Class Codes: H01H 71/125 characterised by sensing elements, e.g. current transformers for differential protection H01H83/144

Abstract

Devices and methods are provided which facilitate detecting of a disturbance parameter being outside a predetermined range. Such disturbance parameter may for example cause dependent failures in redundant circuits, for example redundant circuits being arranged on a same substrate.

Claims

1. A dependency breaking circuit, comprising:

a sensing element sensitive to at least one disturbance parameter,

an output coupled with the sensing element, a signal at the output being dependent on the at least one disturbance parameter such that a fault condition is detected if the disturbance parameter is outside a specified range, and

a transistor coupled between a reference potential and the output, a control input of the transistor being coupled with the sensing element.

2. The circuit of claim 1, wherein the sensing element comprises a voltage divider, the voltage divider comprising a component comprising an impedance of which is sensitive to the disturbance parameter.

3. The circuit of claim 2, wherein the component is selected from a group consisting of a resistor and a transistor.

4. The circuit of claim 1, wherein the sensing element comprises an oscillator, the oscillator being sensitive to a variation of the disturbance parameter.

5. The circuit of claim 4, wherein the oscillator comprises a capacitor sensitive to humidity.

6. The circuit of claim 1, wherein the sensing element comprises an antenna.

7. The circuit of claim 1, wherein the disturbance parameter comprises at least one parameter selected from the group consisting of mechanical stress, carriers in a substrate, electromagnetic radiation, humidity, particle radiation, or temperature.

8. A functional safety device, comprising:

a first dependency breaking circuit, comprising;

a first sensing element sensitive to at least one disturbance parameter, and

a first output coupled with the first sensing element, a signal at the first output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside a specified range; and

a second dependency breaking circuit, comprising;

a second sensing element sensitive to the at least one disturbance parameter, and

a second output coupled with the second sensing element, a signal at the second output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside the specified range,

wherein a first response of the signal at the first output of the first dependency breaking circuit when the at least one disturbance parameter leaves the specified range differs from a second response of the signal at the second output of the second dependency breaking circuit when the at least one disturbance parameter leaves the specified range.

10. The device of claim 8, wherein the first response has a first slope, and the second response has a second slope different from the first slope.

11. The device of claim 10, wherein a sign of the first slope differs from a sign of the second slope.

12. The device of claim 8, wherein the first response comprises a pulling towards a first signal level, and the second response comprises a pulling towards a second signal level different from the first signal level.

13. The device of claim 12, wherein the first signal level is a first voltage potential, and the second signal level is a second voltage potential different from the first voltage potential.

14. The device of claim 8, wherein the first dependency breaking circuit and the second dependency breaking circuit are implemented on a single substrate.

15. The device of claim 8, further comprising an evaluation circuit, the evaluation circuit being responsive to a difference between the signal at the output of the first dependency breaking circuit and the signal at the output of the second dependency breaking circuit.

16. The device of claim 8, further comprising:

a first circuit to provide a predetermined functionality, and

a second circuit to provide the predetermined functionality to provide redundancy.

17. The device of claim 16,

wherein the first dependency breaking circuit is coupled with the first circuit to modify an output of the first circuit when the at least one disturbance parameter is outside the specified range, and

wherein the second dependency breaking circuit is coupled with the second circuit to modify an output of the second circuit when the at least one disturbance parameter is outside the specified range, a modification of the output of the first circuit being different from a modification of the output of the second circuit.

9. A functional safety device, comprising:

a first circuit to provide a predetermined functionality, and

a second circuit to provide the predetermined functionality to provide redundancy, and

a dependency breaking circuit, comprising;

a sensing element sensitive to at least one disturbance parameter, and an output coupled with the sensing element, a signal at the output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside a specified range,

wherein the dependency breaking circuit is coupled with the first circuit to modify an output of the first circuit when the at least one disturbance parameter is outside the specified range.

18. The device of claim 9, wherein the first circuit and the second circuit are provided on a single substrate.

19. The device of claim 9,

wherein the first circuit has a substantially identical circuit design as the second circuit.

20. A functional safety device, comprising:

a first circuit to provide a predetermined functionality when at least one disturbance parameter is within a specified range, and

a second circuit to provide the predetermined functionality when the at least one disturbance parameter is within the specified range to provide redundancy, wherein the first circuit is detuned with respect to the second circuit to cause a first signal of the first circuit to deviate from a second signal of the second circuit by more than a predetermined tolerance when the at least one disturbance parameter is outside the specified range.

21. The device of claim 20, wherein the first circuit comprises a bandgap reference circuit, and wherein the second circuit comprises a bandgap reference circuit detuned with respect to the first bandgap reference circuit.

22. The device of claim 20, wherein the first circuit has a substantially identical circuit design as the second circuit, wherein components of the first circuit are modified compared to the second circuit to provide the detuning.

23. A method, comprising:

measuring a first signal at a first output of a circuit on a substrate, the circuit being sensitive to at least one disturbance parameter,

measuring a second signal at a second output of the circuit, and

deciding that the at least one disturbance parameter is outside a specified range, if a property of the first signal differs from the property of the second signal by more than a predetermined tolerance, wherein the circuit comprises;

a first dependency breaking circuit, comprising;

a first sensing element sensitive to at least one disturbance parameter, and

a first output coupled with the first sensing element, a signal at the first output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside a specified range; and

a second dependency breaking circuit, comprising;

a second sensing element sensitive to the at least one disturbance parameter, and

a second output coupled with the second sensing element, a signal at the second output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside a specified range,

wherein a first response of the signal at the first output of the first dependency breaking circuit when the at least one disturbance parameter leaves the specified range differs from a second response of the signal at the second output of the second dependency breaking circuit when the at least one disturbance parameter leaves the specified range,

wherein the first output of the circuit is coupled to the first output of the first dependency breaking circuit, and the second output of the circuit is coupled to the second output of the second dependency breaking circuit.

25. The method of claim 23,

wherein the property is selected from a group consisting of a voltage, a current, a duty cycle, a frequency or a pulse form.

24. A method, comprising:

measuring a first signal at a first output of a circuit on a substrate, the circuit being sensitive to at least one disturbance parameter,

measuring a second signal at a second output of the circuit, and

deciding that the at least one disturbance parameter is outside a specified range, if a property of the first signal differs from the property of the second signal by more than a predetermined tolerance, wherein the circuit comprises;

a first circuit to provide a predetermined functionality, and

a second circuit to provide the predetermined functionality to provide redundancy, and

a dependency breaking circuit, comprising;

a sensing element sensitive to the at least one disturbance parameter, and an output coupled with the sensing element, a signal at the output being dependent on the at least one disturbance parameter such that a fault condition is detected if the at least one disturbance parameter is outside a specified range,

wherein the dependency breaking circuit is coupled with the first circuit to modify an output of the first circuit when the at least one disturbance parameter is outside the specified range,

wherein the first output of the circuit is coupled to an output of the first circuit, and the second output of the circuit is coupled to an output of the second circuit.