Magnetic Field Sensor

Patent metadata

Field	Value
Publication number	US-2016252599-A1
Application number	US-201615053809-A
Country	US
Kind code	A1
Filing date	Feb 25, 2016
Priority date	Feb 27, 2015
Publication date	Sep 1, 2016
Grant date	—

Abstract

Devices and methods are provided where switches associated with a magnetic field sensor are used to provide error information. In particular, a device is provided that includes a magnetic field sensor, a plurality of switches associated with the magnetic field sensor, and a control circuit configured to control the plurality of switches and to provide at least one signal indicative of a fault based on operation of the switches.

First claim

What is claimed is:

1 . A device, comprising:
a magnetic field sensor, a plurality of switches associated with the magnetic field sensor, and a control circuit configured to control the plurality of switches and to provide at least one signal indicative of a fault based on operation of the switches.

2 . The device of claim 1 , wherein the control circuit is configured to control at least some of the plurality of switches to apply a spinning current scheme to the magnetic field sensor, the spinning current scheme comprising a plurality of phases where different terminals of the magnetic field sensor are used for biasing and for readout.

3 . The device of claim 2 , wherein the control circuit is configured to form at least two partial sums over readout results of the plurality of phases to provide the at least one signal.

4 . The device of claim 3 , wherein the control circuit is configured to provide a signal indicating an error in case a difference between two of the partial sums exceeds a predetermined threshold.

5 . The device of claim 2 , wherein the control circuit is configured to obtain an offset based on readout results of the plurality of phases.

6 . The device of claim 1 , wherein the control circuit is configured to control at least one of the plurality of switches to inject an error current to the magnetic field sensor, and further configured to evaluate a correct operation of providing the at least one signal indicative of a fault based on the injected error current.

7 . The device of claim 1 , wherein the control circuit is configured to control at least one of the plurality of switches to measure at least one of a bias current or a bias voltage biasing the magnetic field sensor.

8 . The device of claim 7 , further comprising a first analog-to-digital converter configured to measure an output of the magnetic field sensor representative of a magnetic field, and a second analog-to-digital converter configured to measure the at least one of the biasing current or the biasing voltage.

9 . The device of claim 7 , further comprising an analog-to-digital converter, the analog-to-digital converter being configured to measure an output signal of the magnetic field sensor indicative of a magnetic field and further being configured to measure the at least one of the biasing current or the biasing voltage.

10 . The device of claim 7 , further comprising at least one analog-to-digital converter configured to measure at least one further quantity.

11 . The device of claim 1 , further comprising an output to provide the at least one signal to a further entity to allow the further entity to determine a possible fault.

12 . The device of claim 1 , wherein the device is an integrated device on a single chip.

13 . The device of claim 1 , wherein the magnetic field sensor comprises a Hall sensor.

14 . A magnetic field sensor device, comprising:
a magnetic field sensor, the magnetic field sensor comprising a plurality of terminals; a biasing source; at least one analog-to-digital converter; a plurality of switches; a controller, the controller being configured to control the plurality of switches to couple the biasing source and the analog-to-digital converter selectively with the plurality of terminals during a plurality of phases; and a summing circuit to provide at least two partial sums of outputs of the analog-to-digital converter in different phases of the plurality of phases.

15 . The device of claim 14 , wherein the controller is further configured to evaluate a difference between the plurality of partial sums, and to output an error signal if the difference exceeds a threshold value.

16 . The device of claim 14 , wherein the controller is further configured to combine the outputs of the analog-to-digital converter in different phases to determine an offset of the device.

17 . A method, comprising:
providing a magnetic field sensor; controlling switches associated with the magnetic field sensor, wherein controlling the switches comprises controlling at least some of the switches to provide a spinning current readout in a plurality of phases; and providing error information based on controlling the switches.

18 . The method of claim 17 , wherein providing error information comprises calculating at least two partial sums of the spinning current readouts, and evaluating a difference between the partial sums.

19 . The method of claim 17 , wherein providing error information comprises calculating an offset based on the spinning current readouts.

20 . The method of claim 17 , wherein controlling the switches comprises controlling at least some of the switches for at least one of providing additional error information, providing additional trimming measurements or providing additional diagnosis measurements.

Assignees

• Infineon Technologies Ag

Inventors

• Motz Mario
• Scherr Wolfgang

Classifications

• G01R33/0041 Primary

  using feed-back or modulation techniques · CPC title

• G01R35/00 Primary

  Testing or calibrating of apparatus covered by the other groups of this subclass · CPC title

• G01R33/075 Primary

  Hall devices configured for spinning current measurements · CPC title