Sensor circuit, a sensor device and a method for forming a sensor circuit

Patent metadata

Field	Value
Publication number	US-2019316935-A1
Application number	US-201916456905-A
Country	US
Kind code	A1
Filing date	Jun 28, 2019
Priority date	Dec 23, 2014
Publication date	Oct 17, 2019
Grant date	—

Abstract

A sensor circuit includes a plurality of half-bridge sensor circuits. The sensor circuit includes a sensor output value determination circuit configured to determine a sensor output value. The sensor circuit further includes an error determination circuit configured to generate an error signal based on a first half-bridge sensor signal and a second half-bridge sensor signal. The sensor circuit further includes a control circuit configured to control a selection of one of the first half-bridge sensor circuit and the second half-bridge sensor circuit for providing one of the first half-bridge sensor signal and the second half-bridge sensor signal to the sensor output value determination circuit to determine the sensor output value.

First claim

What is claimed is:

1 . A sensor circuit comprising:
a plurality of half-bridge sensor circuits; a sensor output value determination circuit configured to determine a sensor output value based on at least one half-bridge sensor signal provided by one of the half-bridge sensor circuits of the plurality of half-bridge sensor circuits; an error determination circuit configured to generate an error signal based on a first half-bridge sensor signal generated by a first half-bridge sensor circuit of the plurality of half-bridge sensor circuits and a second half-bridge sensor signal generated by a second half-bridge sensor circuit of the plurality of half-bridge sensor circuits; and a control circuit configured to control, based on the error signal, a selection of one of the first half-bridge sensor circuit and the second half-bridge sensor circuit for providing one of the first half-bridge sensor signal and the second half-bridge sensor signal to the sensor output value determination circuit.

2 . The sensor circuit according to claim 1 , wherein the error determination circuit is configured to generate the error signal based on a comparison, an addition, or a subtraction of the first half-bridge sensor signal and the second half-bridge sensor signal.

3 . The sensor circuit according to claim 1 , wherein the error determination circuit is configured to generate the error signal based on a comparison, an addition, or a subtraction of a further half-bridge sensor signal generated by a further half-bridge sensor circuit of the plurality of half-bridge sensor circuits, and the first half-bridge sensor signal or the second half-bridge sensor signal.

4 . The sensor circuit according to claim 1 , wherein the first half-bridge sensor circuit and the second half-bridge sensor circuit are formed adjacently on a common semiconductor substrate.

5 . The sensor circuit according to claim 1 , wherein the first half-bridge sensor circuit comprises a first magnetoresistive structure having a first predefined reference magnetization direction, and wherein the second half-bridge sensor circuit comprises a second magnetoresistive structure having a second predefined reference magnetization direction substantially opposite to the first magnetization direction.

6 . The sensor circuit according to claim 5 , wherein the first magnetoresistive structure is electrically coupled in series to the second magnetoresistive structure of the first half-bridge sensor circuit between a supply voltage terminal and a reference voltage terminal, wherein the first half-bridge sensor signal is provided at a node between the first magnetoresistive structure and the second magnetoresistive structure.

7 . The sensor circuit according to claim 5 , wherein the first magnetoresistive structures having the first predefined reference magnetization direction are formed in a first common area of the common semiconductor substrate, and wherein the second magnetoresistive structures having the second predefined reference magnetization direction are formed in a second common area of the common semiconductor substrate, wherein the second common area is different from the first common area.

8 . The sensor circuit according to claim 5 , wherein the first magnetoresistive structures having the first predefined reference magnetization direction are formed at a first layer level of the common semiconductor substrate, and wherein the second magnetoresistive structures having the second predefined reference magnetization direction are formed at a second layer level of the common semiconductor substrate, wherein the second layer level is different from the first layer level.

9 . The sensor circuit according to claim 1 , wherein each half-bridge sensor circuits of the plurality of half-bridge sensor circuits comprise a first magnetoresistive structure and a second magnetoresistive structure, wherein the first magnetoresistive structure and the second magnetoresistive structure of the same half-bridge sensor circuit have different predefined reference magnetization directions.

10 . The sensor circuit according to claim 9 , wherein magnetoresistive structures having a same first predefined reference magnetization direction are formed in a first common area and the magnetoresistive structures having a same predefined second reference magnetization direction are formed in a second common area, wherein the second common area is different from the first common area.

11 . The sensor circuit according to claim 1 , comprising a first full-bridge sensor circuit comprising the first half-bridge sensor circuit and a first complementary half-bridge sensor circuit of the plurality of half-bridge sensor circuits coupled between a supply voltage terminal and a reference voltage terminal; and
a second full-bridge sensor circuit comprising the second half-bridge sensor circuit and a second complementary half-bridge sensor circuit of the plurality of half-bridge sensor circuits coupled between the supply voltage terminal and the reference voltage terminal.

12 . The sensor circuit according to claim 11 , further comprising a third full-bridge sensor circuit comprising a third half-bridge sensor circuit and a third complementary half-bridge sensor circuit of the plurality of half-bridge sensor circuits coupled between the supply voltage terminal and the reference voltage terminal; and
a fourth full-bridge sensor circuit comprising a fourth half-bridge sensor circuit and a fourth complementary half-bridge sensor circuit of the plurality of half-bridge sensor circuits coupled between the supply voltage terminal and the reference voltage terminal.

13 . The sensor circuit according to claim 1 , wherein the plurality of half-bridge sensor circuits comprises a third half-bridge sensor circuit configured to provide a third half-bridge sensor signal having a predefined phase-offset with respect to at least one of the first half-bride sensor signal and the second half-bridge sensor signal,
wherein the sensor output value determination circuit is configured to determine the sensor output value based on the third half-bridge sensor signal and one of the first half-bridge sensor signal and the second half-bridge sensor signal.

14 . The sensor circuit according to claim 1 , wherein half-bridge sensor circuits of the plurality of half-bridge sensor circuits each comprise a first terminal electrically coupled to a supply voltage terminal and a second terminal electrically coupled to a reference voltage terminal.

15 . The sensor circuit according to claim 1 , further comprising an analog to digital converter circuit and an amplitude offset correction circuit; and
wherein the control circuit comprises at least one multiplexer circuit configured to select at least one further half-bridge sensor circuit of the plurality of half-bridge sensor circuits, and at least one of the first half-bridge sensor circuit and the second half-bridge sensor circuit for providing half-bridge sensor signals for generating the sensor output value, wherein the analog to digital converter circuit is configured to generate a digital sensor signal based on an analog half-bridge sensor signal provided by a half-bridge sensor circuit selected by the at least one multiplexer circuit, and wherein the amplitude offset correction circuit is configured to correct an amplitude offset of the digital sensor signal, wherein the sensor output value is determined based on the corrected digital sensor signal.

16 . The sensor circuit according to claim 1 , further comprising an output interface circuit configured to

Assignees

• Infineon Technologies Ag

Inventors

• Jost Franz
• Witschnig Harald
• Zimmer Juergen

Classifications

• G01R33/0052

  Manufacturing aspects; Manufacturing of single devices, i.e. of semiconductor magnetic sensor chips (devices based on galvano-magnetic effect or the like H10N50/85) · CPC title

• G01D5/16 Primary

  by varying resistance · CPC title

• G01R33/09

  Magnetoresistive devices · CPC title

• G01D3/08

  with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown · CPC title

• G01D5/12 Primary

  using electric or magnetic means (G01D5/06 takes precedence) · CPC title