Systems and methods for offset reduction in sensor devices and systems

Patent metadata

Field	Value
Publication number	US-9720050-B2
Application number	US-201514886864-A
Country	US
Kind code	B2
Filing date	Oct 19, 2015
Priority date	Jan 29, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Embodiments relate to systems and methods for reducing errors in sensor devices and systems. In embodiments, the sensor devices comprise magnetic field sensor devices, such as ordinary or vertical Hall sensor devices, and the error to be reduced is a residual offset error, though in other embodiments other sensor devices can be used and/or other types of errors can be targeted for reduction or elimination. In one embodiment, at least two such sensor devices not electrically coupled with one another are sequentially operated in a spinning current-type mode such that an individual output signal from each of the at least two sensor devices is obtained. A total output signal can then be calculated, such as by averaging or otherwise combining the individual output signals from each sensor device.

First claim

What is claimed is:

1. A sensor system comprising:
a plurality of sensor devices positioned proximate each other such that each of the plurality of sensor devices is configured to sense essentially the same condition, wherein the plurality of sensor devices comprise vertical Hall effect sensor devices;
control circuitry configured to operate each of the plurality of sensor devices in at least one partial spinning current mode comprising at least two phases to obtain a partial spinning current output signal in each phase by selectively coupling a first of the plurality of terminals of each of the plurality of sensor devices as a supply terminal and a second of the plurality of terminals of each of the plurality of sensor devices as a signal terminal such that, in sequential phases, current flows in different directions in each of the plurality of sensor devices; and
output circuitry configured to determine a system output signal from partial spinning current output signals of the at least two phases of each of at least two of the plurality of sensor devices,
wherein the output circuitry is further configured to compare the partial spinning current output signals of the plurality of sensor devices to determine a distribution of the partial spinning current output signals.

2. The sensor system of claim 1 , wherein the output circuitry is configured to determine a system output signal from summing the partial spinning current output signals of at least two of the plurality of sensor devices.

3. The sensor system of claim 1 , wherein the output circuitry is configured to determine a system output signal from averaging the partial spinning current output signals of at least two of the plurality of sensor devices.

4. The sensor system of claim 1 , wherein a first of the Hall effect sensor devices comprises at least one of the same terminals a second of the Hall effect sensor devices, wherein the first and second Hall effect sensor devices are operated in different phases.

5. The sensor system of claim 1 , wherein the control circuitry is configured such that in sequential phases different ones of the plurality of terminals of each of the plurality of sensor devices are operable as signal terminals.

6. The sensor system of claim 1 , wherein the plurality of terminals comprises at least three terminals.

7. The sensor system of claim 1 , wherein the distribution is used to determine a residual offset error affecting at least one of the plurality of sensor devices.

8. The sensor system of claim 1 , wherein the output circuitry is further configured to omit from the determination of the system output signal at least one sensor device partial spinning current output signal that is an outlying signal within the distribution.

9. The sensor system of claim 1 , wherein the control circuitry is configured to omit from operation in a subsequent spinning current mode at least one sensor device having a partial spinning current output signal that is an outlying signal within the distribution.

10. The sensor system of claim 9 , wherein the output circuitry is configured to determine the distribution during a manufacturing test and store a result of the test in a non-volatile memory.

11. The sensor system of claim 1 , wherein the output circuitry is configured to carry out the comparison periodically.

12. The sensor system of claim 1 , wherein the output circuitry is configured to carry out the comparison at least one of stochastically, upon a request, or upon an input.

13. The sensor system of claim 1 , wherein the control circuitry is configured to operate each of the plurality of sensor devices sequentially in a spinning current mode.

14. The sensor system of claim 1 , wherein the control circuitry is configured to operate at least two of the plurality of sensor devices simultaneously in a spinning current mode.

Assignees

• Infineon Technologies Ag

Inventors

• Ausserlechner Udo

Classifications

• G01R33/075

  Hall devices configured for spinning current measurements · CPC title

• G01R33/0017 Primary

  Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields · CPC title

• G01R33/077

  Vertical Hall-effect devices · CPC title

• G01R33/07 Primary

  Hall effect devices · CPC title

• G01R33/0029

  Treating the measured signals, e.g. removing offset or noise · CPC title