Sensor fault detection system and method

Patent metadata

Field	Value
Publication number	US-9791493-B2
Application number	US-201313747250-A
Country	US
Kind code	B2
Filing date	Jan 22, 2013
Priority date	Feb 10, 2012
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Fault detection techniques for control of sensor systems. A sensor control integrated circuit (“IC”) may include a fault detection system for coupling to the sensor supply lines. The system may detect faults for each of the sensor supply lines. The fault detection system may level shift sensor supply line signals from a first voltage domain to a second voltage domain appropriate for the fault detection system of the controller IC. The fault detection system may level shift source potential voltages from the first voltage domain to the second voltage domain to detect predetermined fault types. The fault detection system may compare the second domain voltages from the sensor supply lines to voltages representing predetermined fault types and may generate fault status indicators based on the comparison.

First claim

We claim:

1. A controller integrated circuit (IC) for determining fault status of a sensor operating in a high voltage, sensor voltage domain that exceeds an IC voltage domain of the IC, the controller IC comprising:
a fault detection circuit to convert one or more sensor return signals from the sensor voltage domain to the IC voltage domain and detect one or more predetermined fault types based on a comparison of a respective sensor return signal with an IC voltage domain reference voltage representative of the predetermined fault occurring at the sensor in the sensor voltage domain the fault detection circuit including:
a first level shifter to receive a reference input signal from the sensor voltage domain and to generate a trigger signal in the IC voltage domain;
a second level shifter to receive the one or more sensor return signals from the sensor voltage domain and to generate one or more corresponding level shifted sensor signals within the IC voltage domain; and
a comparator to compare the one or more level shifted sensor signals to the trigger signal to determine whether to generate a first fault status signal representing a detected sensor fault of the predetermined fault type.

2. The circuit of claim 1 , wherein the first level shifter and the second level shifter include high voltage devices operating in the high voltage, sensor voltage domain compared to the IC voltage domain.

3. The circuit of claim 1 , wherein the first level shifter includes a programmable voltage divider network to generate the one or more trigger signals.

4. The circuit of claim 1 , wherein the second level shifter includes a programmable voltage divider network to generate the level shifted one or more sensor signals.

5. The circuit of claim 1 , comprising a fault controller to determine whether a sensor input terminal is disconnected from the sensor.

6. The circuit of claim 1 , wherein the IC further comprises:
multiple sensor input terminals, each for coupling to a respective sensor; and
a multiplexer coupling the fault detection circuit to at least a selected one of the sensor input terminals in response to a control signal.

7. The circuit of claim 1 , wherein the IC further comprises a decoder to process the one or more sensor return signals.

8. The circuit of claim 7 , wherein the receiver is configured to capture the one or more sensor return signals from a sensor operating from a single-ended supply line.

9. The circuit of claim 1 , including:
one or more sensor input terminals; and
a receiver configured to receive the one or more sensor return signals at the one or more sensor input terminals.

10. The circuit of claim 1 , in combination with the sensor.

11. The circuit of claim 10 , wherein the detected sensor fault is an automotive sensor fault.

12. The circuit of claim 10 , wherein the detected sensor fault is a microphone fault.

13. The circuit of claim 10 , wherein the detected sensor fault is a pressure sensor fault.

14. The circuit of claim 10 , wherein the detected sensor fault is a proximity sensor fault.

15. The circuit of claim 10 , wherein the detected sensor fault is a temperature sensor fault.

16. The circuit of claim 1 , wherein the fault detection circuit includes a fault controller configured to receive a fault status signal from the fault detection circuit and to output a fault status indicator representing the detected fault.

17. The circuit of claim 1 , including a driver circuit configured to provide a sensor supply voltage at a sensor supply terminal of the circuit.

18. A controller integrated circuit (IC) for determining fault status of a sensor operating in a high voltage, sensor voltage domain that exceeds an IC voltage domain of the IC, the controller IC comprising:
means for converting one or more sensor return signals from the sensor voltage domain to the IC voltage domain, and for detecting one or more predetermined fault types based on a comparison of a respective sensor return signal with an IC voltage domain reference voltage representative of the predetermined fault occurring at the sensor in the sensor voltage domain, wherein the means for converting and for detecting includes:
means for receiving a reference input signal from the sensor voltage domain and for generating a trigger signal in the IC voltage domain;
means for receiving the one or more sensor return signals from the sensor voltage domain and for generating one or more corresponding level shifted sensor signals within the IC voltage domain; and
means for comparing the one or more level shifted sensor signals to the trigger signal to determine whether to generate a first fault status signal representing a detected sensor fault of the predetermined fault type.

19. The circuit of claim 18 , including means for processing the sensor return signals to provide sensor information.

20. The circuit of claim 18 , wherein the fault detection means includes means for receiving a fault status signal from the fault detection means and providing a fault status indicator representing a detected fault type.

21. The circuit of claim 18 . including means for providing a sensor supply voltage at a sensor supply terminal of the circuit.

22. The circuit of claim 18 , wherein the IC includes means for coupling a respective sensor.

23. The circuit of claim 18 , wherein the IC includes means for receiving a control signal and means for coupling a selected one of the means for coupling a respective sensor to the means for converting in response to the control signal.

24. A controller integrated circuit (IC), comprising:
a driver to drive a first domain sensor source voltage to a sensor supply terminal of the IC;
a receiver to capture sensor return signals at a sensor input terminal of the IC;
a fault detection system to convert the sensor return signals from a sensor voltage domain to an IC voltage domain and detect a predetermined fault types based on comparisons of the converted signals with IC domain reference voltages representative of the predetermined fault types occurring at a sensor in the sensor voltage domain;
a fault controller to receive fault status signals from the fault detection system and output fault status indicators representing detected fault types;
wherein operating voltages for the sensor return signals in the sensor voltage domain exceed operating voltages for the corresponding converted signals in the IC voltage domain; and
wherein the fault detection system includes a plurality of fault detection circuits, each fault detection circuit of the plurality of fault detection circuits comprising:
a first level shifter to receive a reference input signal from the sensor voltage domain and to generate a trigger signal in the IC voltage domain;
a second level shifter to receive the sensor return signals from the sensor voltage domain and to generate level shifted sensor signals within the IC voltage domain; and
a comparator to compare the level shifted sensor signals to the trigger signal, wherein the comparator generates a first fault status signal representing a detected predetermined sensor fault.

25. The circuit of claim 24 , wherein the first level shifter and the second level shifter are high voltage devices compared to the IC voltage domain.

26. The circuit of claim 24 , wherein the first level shifter includes a programmable voltage divider network to generate the trigger signals.

Assignees

• Analog Devices Inc

Inventors

• Bandyopadhyay Abhishek
• Nguyen Khiem Quang

Classifications

• H04R29/004 Primary

  for microphones (H04R29/007 takes precedence) · CPC title

• G01R31/50

  Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections (testing of sparking plugs H01T13/58) · CPC title

• H04R2420/05

  Detection of connection of loudspeakers or headphones to amplifiers · CPC title

• G01R31/2829

  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 title

• G01D3/10

  with provision for switching-in of additional or auxiliary indicators or recorders · CPC title