Giant Magneto Resistive Position Sensor
Version 1.0
GMR S 4
Data Sheet
1
1999-04-01
Data Sheet
This angle sensor is based on the brand new Giant Magneto Resistive (GMR)
technology. It is outstanding for the huge tolerances it offers to the user in
assembly.
x
new type
The GMR S 4 is an angle sensor based on sputtered metallic multilayer technology. 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.
Type
Marking
Ordering Code
x
GMR S 4
s
Q62705-K5002
Features
GMR sensor on copper
leadframe
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 sensing with large air
gaps according to sketch below
Angle encoders
Contactless potentiometers
Pin Configuration
1, 2
supply voltage
terminals
3, 4
not connected
Dimensions in mm
Internal magnetization is in direction of the longest side of the
housing.
GPX06981
4
3
2
1
12.3
11.7
2.1
2.3
4.7
4.3
0.55
0.15
3.2
3.0
0.15
1.5
Injection flash
Flash 0.1 max
0.1 max
3 x 1.27 = 3.81
spacing
Chip center
0.35
0.55
0.5
0.35
0.2
0.3
0.7
0.6
0.28
0.1
Chip
Approx. weight 0.05 g
1, 2 GMR access
3, 4 not connected
A
0.3
0.15
A
Directions of internal magnetization
GMR S 4
Data Sheet
2
1999-04-01
Maximum Ratings
Parameter
Symbol
Value
Unit
Operating temperature
T
A
40 ... + 150
C
Storage temperature
T
stg
50 ... + 150
C
Supply current
I
1
5
mA
Thermal conductivity
G
thC
A
G
thC
C
> 2.2
> 5
mW/K
mW/K
Magnetic field
1)
1)
larger fields may reduce the magnetoresistive effect irreversibly
H
rot
< 15
kA/m
OHS00375
Resistance
0
180
360
Rotating
Magnet
GMR Sensor
Output signal vs orientation of magnet
R = R
0
+ 0.5
R *
)
(1-cos
N
S
*
Principle of operation
Angle
GMR S 4
Data Sheet
3
1999-04-01
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 when a fullbridge circuit is used. In the case of
linear position sensing, the electrical circuit remains unchanged.
Characteristics (
T
A
= 25
C)
Parameter
Symbol
Value
Unit
Nominal supply current
I
1N
4
mA
Basic resistance
R
0
> 700
Magnetoresistive effect
H
rot
= 5 ... 15 kA/m
R
/
R
0
4
%
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
Hysteresis at
H
rot
= 10 kA/m
Hys
< 2
degrees
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