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.
◆new type
TheGMRS4isanangle 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 TC(R,∆R)is
possible.
Type Marking Ordering Code
◆GMR S 4 ■Q62705-K5002
Features
• GMR sensor on copper
leadframe
•Sensitive to the direction, not
to the intensity of the magnetic
field
• Constant TCof 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
0.3ø0.15
A
Directions of internal magnetization
GMRS4
Data Sheet 2 1999-04-01
Maximum Ratings
Parameter Symbol Value Unit
Operating temperature TA– 40 … + 150 °C
Storage temperature Tstg – 50 … + 150 °C
Supply current I15mA
Thermal conductivity GthC A
GthC C> 2.2
> 5 mW/K
mW/K
Magnetic field 1)
1) larger fields may reduce the magnetoresistive effect irreversibly
Hrot < 15 kA/m
OHS00375
Resistance
0˚ 180˚ 360˚
Rotating
Magnet
GMR Sensor
Output signal vs orientation of magnet
R
=
R
0
+ 0.5 ∆
R
*α)(1-cos
NS
*
Principle of operation
Angle
GMRS4
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 TCof the resistance value
R0. To compensate for the TCof the GMR effect ∆R/R0, 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 (TA = 25 °C)
Parameter Symbol Value Unit
Nominal supply current I1N 4mA
Basic resistance R0> 700 Ω
Magnetoresistive effect
Hrot = 5 ... 15 kA/m ∆R/R0≈4%
Temperature coefficient of
basic resistance TCR0 + 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 Hrot = 10 kA/m Hys < 2 degrees
