Cascade magnetic sensor circuit and a linear magnetic sensor device comprising the cascade magnetic sensor circuit

Patent metadata

Field	Value
Publication number	US-2026029491-A1
Application number	US-202318997642-A
Country	US
Kind code	A1
Filing date	Jul 21, 2023
Priority date	Jul 22, 2022
Publication date	Jan 29, 2026
Grant date	—

Abstract

The present disclosure concerns magnetic sensor device (10) for sensing an external magnetic filed vector (H) comprising a cascade magnetic sensor circuit (100) comprises N magnetic sensors (2n), wherein N equal to or greater than 2, wherein said N magnetic sensors (2n) comprises a first magnetic sensor (21) and at least another magnetic sensor (2n) electrically connected in cascade with each other. The first magnetic sensor (21) is configured to generate a first output voltage (Vout1) dependent on an external magnetic field vector (H) when inputted with an input bias voltage (Vdd). The output voltage of the nth magnetic sensor is used as input bias voltage of the next (n+1) magnetic sensor. The magnetic sensor device (10) further comprises at least one reference magnetic field sensor (2Ref). The corrected output voltage has improved linearity compared to the reference output voltage.

First claim

1 . A magnetic sensor device for sensing an external magnetic field vector (H) comprising a cascade magnetic sensor circuit comprising N magnetic sensors (2 n ), each magnetic sensors (2 n ) generating an output voltage (V outn ), wherein N equal to or greater than 2, wherein the magnetic sensors (2 n ) are electrically connected in cascade with each other;
wherein the output voltage (V outn ) of the n th magnetic sensors (2 n ) is proportional to an input bias voltage (V 0_n ) of the n th magnetic sensor ( 2 n ) and to a normalized output voltage (v s_n (H)) of the n th magnetic sensor ( 2 n ) depending on the external magnetic field vector (H):

V

o
⁢
u
⁢
t
⁢
n

=

v

s
⁢
_
⁢
n

(
H
)

·

V

0
⁢

_
⁢
n

wherein the output voltage (V outn ) of one of the n th magnetic sensors (2 n ) supplies the input bias voltage (V 0_n+1 ) of the (n+1) th magnetic sensor ( 2 n+1 );
characterized in that the magnetic sensor device ( 10 ) further comprises at least one reference magnetic field sensor ( 2 Ref );
wherein a corrected output voltage (V corr ) of the magnetic sensor device is determined by:

V

c
⁢
o
⁢
r
⁢
r

=

a
·

V
outRef

+

b
·

V

o
⁢
u
⁢
t
⁢
Cascade

where a and b are correction parameters independent of the external magnetic field vector (H), V outRef is a reference output voltage generated by at least one reference magnetic sensor ( 2 Ref ), the corrected output voltage (V corr ) having improved linearity compared to the reference output voltage (V outRef ), and V outCascade is the cascade output voltage of the cascade magnetic sensing circuit.

2 . The magnetic sensor device according to claim 1 ,
wherein the cascade sensor circuit is configured to generate an output voltage (V outCascade ):

V
outCascade

=

V
0

·

∏

n
=
1

N

⁢

v

s
n

(
H
)

,

where v s_n is the normalized output voltage of the n th magnetic sensor of the cascade magnetic sensor circuit and V 0 is the input bias voltage of the first magnetic sensor of the cascade magnetic sensor circuit.

3 . The magnetic sensor device according to claim 1 , comprising a first magnetic sensor ( 2 1 ) cascade connected to at least another magnetic sensor ( 2 n );
the normalized output voltage (v s_n (H)) of each magnetic sensor ( 2 n ) having a substantially identical dependence on the external magnetic field vector (H); and wherein the cascade magnetic sensor circuit generates an output voltage (V outCascade ) that is proportional to a degree N with respect to the normalized output voltage (v s_1 (H)) of the first magnetic sensor ( 2 1 ) and to the input bias voltage (V 0 ) inputted to the first magnetic sensor (v out1 ) of the cascade sensor circuit:

V
outCascade

=

V
0

·

v

s
⁢
_

⁢
1

N

.

4 . The magnetic sensor device according to claim 2 , comprising an amplification stage (g n ) at the output of at least 1 of the N magnetic sensors of the cascade circuit, wherein the cascade sensor circuit is configured to generate an output voltage (V outCascade ):

V
outCascade

=

V
0

·

∏

n
=
1

N

⁢

g
n

·

v

s
n

(
H
)

.

5 . The magnetic sensor device according to claim 4 , wherein an additional positive or negative voltage signal (V add_n ) is added to the output voltage V outn of at least one of t

Assignees

• Allegro Microsystems Llc

Inventors

• Serrano-Guisan Santiago
• Mohan Anuraag

Classifications

• G01R33/098

  comprising tunnel junctions, e.g. tunnel magnetoresistance sensors · CPC title

• G01R33/0094 Primary

  Sensor arrays · CPC title

• G01R33/0029 Primary

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

• G01R33/09

  Magnetoresistive devices · CPC title