System for Magnetic Self Test

• US 20150102804A1
• Filed: 10/13/2014
• Published: 04/16/2015
• Est. Priority Date: 10/14/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Hammerschmidt, Dirk, Heinrichs, Frank
• Granted Patent: US 10,527,701 B2
• Time in Patent Office: Days
• US Class Current: 324/202
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• 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: G01R 33/0017 Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields
• CPC Class Codes: G01R 33/0035 Calibration of single magnetic sensors, e.g. integrated calibration
• CPC Class Codes: G01R 35/00 Testing or calibrating of apparatus covered by the other groups of this subclass

Abstract

The disclosure provides a system for magnetic self test. The system includes an electronic control unit (ECU) including a controller. Only one sensor is electrically coupled to the ECU, wherein the sensor includes a sensing element, a signal conditioning element electrically coupled to the sensing element and the controller, and a wire-on-chip (WOC) device disposed next to the sensing element. The system further includes a WOC stimulus element provided in the ECU or the sensor to drive the WOC to create a WOC magnetic field, wherein the system is configured to compare an expected sensor output signal that is caused by the WOC magnetic field with an actual sensor output signal by the controller or an additional signal assessment element in the sensor to identify whether the sensor is still functioning correctly.

Claims

1. A system for magnetic self test, comprising:

an electronic control unit (ECU) including a controller;

only one sensor electrically coupled to the ECU, wherein the sensor comprises a sensing element, a signal conditioning element electrically coupled to the sensing element and the controller, and a wire-on-chip (WOC) device disposed next to the sensing element;

a WOC stimulus element provided in the ECU or the sensor to drive the WOC device to create a WOC magnetic field,

wherein the system is configured to compare an expected sensor output signal that is caused by the WOC magnetic field with an actual sensor output signal by the controller or an additional signal assessment element in the sensor to identify whether the sensor is still functioning correctly.

2. The system of claim 1, wherein the WOC stimulus element is provided in the ECU and receives the command signal from the controller to drive the WOC device.

3. The system of claim 1, wherein the WOC stimulus element is provided in the sensor and receives the command signal from the controller to drive the WOC device.

4. The system of claim 1, wherein the sensor further comprises an integrated energy storage device, wherein the energy storage device is powered by an external supply and electrically coupled to the WOC stimulus element provided in the sensor to avoid high current consumption peaks of the sensor during the magnetic self test.

5. The system of claim 4, wherein the energy storage device is one or more capacitors in series or parallel connection.

6. The system of claim 1, wherein the sensor further comprises one or more integrated capacitors parallel connected with the WOC device, wherein the inductor of the WOC device and the integrated capacitor form a resonant circuit that is excited by an internal driver device, the enabling input of which is connected to the WOC stimulus element.

7. The system of claim 6, wherein the internal driver device is an amplifier.

8. The system of claim 6, wherein the WOC stimulus element and the controller are configured to not be synchronized in real-time with a synchronization signal sent from the WOC stimulus element to the controller being not needed.

9. The system of claim 6, wherein the WOC stimulus element is configured to send a synchronization signal to the controller so as to achieve real-time synchronization between the WOC stimulus element and the controller.

10. The system of claim 6, wherein the WOC stimulus element is configured to send a synchronization signal to the additional signal assessment element rather than the controller so as to achieve real-time synchronization between the WOC stimulus element and the additional signal assessment element.

11. The system of claim 8, wherein the synchronization signal is derived from the resonant circuit or the internal driver device and the additional signal assessment element contains a synchronous demodulation of the sensor output signal.