Giant Magneto Resistive Position Sensor
Version 2.0
GMR B6
Data Sheet
1
2000-07-01
This angle sensor is based on the Giant Magneto Resistive (GMR) technology.
It is outstanding for the huge tolerances it offers to the user in assembly.
6, 3
supply
5 (= 2)
ground
1, 4
GMR bridge access
Type
Marking
Ordering Code
GMR B6
B
Q62705-K5004
Features
GMR sensor in SMD package
Sensitive to the direction,
not to the intensity of the
magnetic field
Constant
T
C
of basic
resistance
R
and magneto
resistance
R
Applications
Rotation and linear sensing
with large airgaps
Angle encoders
Contactless potentiometers
Incremental encoders
Pin Configuration
OHS00429
2
R
R
1
3
R
R
4
1
4
6
3
2/5
Dimensions in mm
0.3
-0.05
+0.1
+0.1
-0.05
0.6
6
4
1
B
A
0.25
M
B
0.08 ... 0.15
1.1 max
2 ... 30
2.6 max
10 max
10 max
0.1 max
A
M
0.20
2.9
0.1
1.3
0.1
2
3
5
1.9
GPW06957
0.2
0.15
0.35
0.3
0.1
1.2
3
0.8
0.3
0.5
0.45
0.9
Reflow soldering
Directions of internal
magnetization
GMR B6
Data Sheet
2
2000-07-01
The GMR B6 is an angle sensor based on sputtered metallic multilayer technology.
4 resistors are monolithically integrated on 1 chip. They can be used as a fullbridge or,
if 2 external resistors are added, as 2 halfbridges. The outstanding feature of this
magnetic sensor is the fact, that it is sensitive to the orientation of the magnetic field and
not to its intensity as long as the field is in a range between 5 ... 15 kA/m. This means,
the signal output of this sensor is independent of the sensor position relative to the
magnet in lateral, axial or rotational direction in the range of several millimeters.
Optimum results are achieved by using magnetic targets like permanent magnets or
magnetic pole-wheels. There is no need for a biasing magnet! Due to the linear change
of both, basic and field dependent part of the resistance vs. temperature, simple and
efficient electronic compensation of
T
C
(
R
,
R
) is possible.
Figure 1
Output Voltage of Half Bridges (V1, V4) and Full Bridge (V4 - V1) as a Function of
the Magnetic Field Orientation
GMR B6
N
S
Bridge Voltage
[
(
V
O
)/2
]
-1
0
AED02956
-0.5
0
0.5
1
90
180
270
Deg
360
V
4
V
1
V
1
-
V
4
Angle
R
R
O
GMR B6
Data Sheet
3
2000-07-01
Application Hints
The application mode of the GMR position sensor is preferably as a bridge or halfbridge
circuit. In every case this type of circuit compensates for the
T
C
of the resistance value
R
0
. To compensate for the
T
C
of the GMR effect
R
/
R
0
, if there is the necessity, is left to
the application circuit and can be done for example with a NIC circuit. When operated
over a complete 360
turn, a total signal of
20 mV/V is achieved at 25
C with a
halfbridge. The output signal is doubled to of
40 mV/V when a fullbridge circuit is used.
In the case of linear position sensing, the electrical circuit remains unchanged.
Maximum Ratings
Parameter
Symbol
Value
Unit
Operating temperature
T
A
40 ... + 150
C
Storage temperature
T
stg
50 ... + 150
C
Supply voltage
V
1
7
V
Thermal conductivity
G
thC
A
> 4
mW/K
Magnetic field
1)
H
rot
< 15
kA/m
1)
larger fields may reduce the magnetoresistive effect irreversibly
Characteristics (
T
A
= 25
C)
Parameter
Symbol
Value
Unit
Nominal supply voltage
V
1N
5
V
Basic resistance
R
0
> 700
Magnetoresistive effect
H
rot
= 5 ... 15 kA/m
R
/
R
0
> 4
%
Output signal fullbridge
@
V
1N
= 5 V
V
OUT
> 200
mV
Offset voltage
@
V
1N
= 5 V |
V
0
|
< 8
mV
Temperature coefficient of
basic resistance
TC
R0
+ 0.09 ... + 0.12
%/K
Temperature coefficient of
magnetoresistance
TC
R
0.12 ... 0.09
%/K
Temperature coefficient of
magnetoresistive effect
TC
R/R0
0.27 ... 0.23
%/K
GMR B6
Data Sheet
4
2000-07-01
Output Voltage Degradation (typical) at
high Temperature Operation
Basic Resistance (typical) versus
Temperature
R
0
=
f
(
T
A
)
Magnetoresistive Effect (typical) versus
Temperature
R
/
R
0
=
f
(
T
A
)
AED02953
95
A
T
= 150 C
2
10
10
3
10
4
96
97
98
99
100
%
Output Voltage (normalized)
Operation Time
h
= 125 C
T
A
= 105 C
T
A
AED02954
T
80
-40 -20 0 20 40 60 80 100
150
90
100
110
120
C
%
Resistance (normalized)
AED02959
T
60
-50
C
70
80
90
100
110
120
%
Magnetoresistive Effect (normalized)
-10
30
70
110
150
PDF 
ZIP