KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
1/9
KMY22 KMY20 KMZ20
AMR sensor
Very high sensitivity
Almost no hysteresis
Various applications
Available with internal magnet
Available in several packages
DESCRIPTION
Due to its featured properties - high sensitivity and almost no hysteresis – the KMY / KMZ sensors are used
in a wide range of applications, like magnetic field measurement, revolution counters, proximity detecting,
and position measurement.
An uniaxial linear magnetic field will generate a linear output within the specified magnetic field range.
FEATURES APPLICATIONS
Output proportional to magnetic field
strength with very high sensitivity
Detection of very weak magnetic fields, like
earth magnetic field, or field generated by
small magnetic particles
Very small hysteresis
Detection of objects that distort non-local
magnetic fields
Large operating temperature range, from -
40°C up to +150 °C
Revolution measurement on ferromagnetic
gears
Highly reliable
Contactless switch
With / without internal magnet
Contactless displacement / position sensor
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
2/9
DESCRIPTION
An uniaxial linear magnetic field (in y-direction) will generate a linear output within the specified magnetic
field range. The sensor is available in two types: the KMY 20 M, KMY 21 M and KMZ 20 M sensor types
contain intrinsic magnets which provide an auxiliary magnetic field (in x-direction) at the sensor die which
prevents magnetic domains from flipping irregularly.
If the dies MR174B or the
components KMY22, KMY20S
or KMZ20S are used, the
auxiliary field has to be provided
by the user. The dependence of
the sensitivity with auxiliary field
strength is depicted in the figure
aside.
Figure 1: Sensitivity dependence on
auxiliary field strength
Auxiliary Field Dependence
0
5
10
15
0 1 2 3 4 5
Hx in kA/m
S in mV/V/kA/m
Auxiliary field strengths below Hx<1.5 kA/m are not recommended, as small disturbances may flip the
magnetization domains. Sometimes, the magnetic conditions in the application may provide enough Hx bias
field stabilization. MEAS Germany can provide advise for customer specific magnet arrangements.
If a bias field Hx is not applied
or Hx is less than 2.5 kA/m, the
sensor may be used only in a
limited field range Hy,
depending on the present total
bias field Hx,tot. In this case, it
is strongly recommended to
‘premagnetize’ the sensor, i.e.
align all magnetic domains
consistently, prior to the
measurement.
Hx,tot is the sum of all acting
magnetic fields in x direction at
the sensor die.
Do not use the sensor outside
the safe operating area.
Leaving the save operating area
can destroy an existing
premagnetization and therefore
will lead to unreproducible
sensor signals.
Figure 2: Safe operating area
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
3/9
CHARACTERISTIC VALUES / SENSOR SPECIFICATIONS
Parameter
Symbol
Condition
Min
Typ
Max
Unit
Operating Limits
max. supply voltage
Vcc,max
10
V
max. current
Icc,max
9
mA
operating temperature
Top
-40
+150
C
storage temperature
Tst
-40
+150
C
General Sensor Specifications
TC of amplitude
TCSV
Condition A, C
-0.36
-0.32
-0.28
%/K
TC of resistance
TCBR
Condition A, C
+0.27
+0.32
+0.37
%/K
TC of offset
TCVoff
Condition A, C
-4
0
+4
µV/V/K
Sensor Specifications KMY 20 S, KMZ 20 S (T=25 °C, Hx=3 kA/m externally)
Supply voltage
Vcc
Condition A, B
5
V
Bridge resistance
Rb
Condition A, B
1200
1700
2200
Output signal range
V0/Vcc
Condition A, B
16
20
24
mV/V
Offset voltage
Voff/Vcc
Condition A, B
-1
0
+1
mV/V
Sensitivity
S
Condition A, B
3.7
4.7
5.7
mV/V/kA/m
Hysteresis
VH/Vcc
Condition A, B
-
-
50
µV/V
Sensor Specifications KMY 20 M, KMZ 20 M (T=25 °C, Hx=1.5±0.5 kA/m internally)
Supply voltage
Vcc
Condition A, B
5
V
Bridge resistance
Rb
Condition A, B
1200
1700
2200
Output signal range
V0/Vcc
Condition A, B
16
20
24
mV/V
Offset voltage
Voff/Vcc
Condition A, B
-1.5
0
+1.5
mV/V
Sensitivity
S
Condition A, B
4
5.5
7
mV/V/kA/m
Hysteresis
VH/Vcc
Condition A, B
-
-
50
µV/V
Sensor Specifications KMY 21 M (T=25 °C, Hx=2.5±1.0 kA/m internally)
Supply voltage
Vcc
Condition A, B
5
V
Bridge resistance
Rb
Condition A, B
1100
1500
1900
Output signal range
V0/Vcc
Condition A, B
8
9.5
12
mV/V
Offset voltage
Voff /Vcc
Condition A, B
48
50
52
%Vcc
Sensitivity
S
Condition A, B
2.05
2.50
3.10
mV/V/kA/m
Hysteresis
VH/Vcc
Condition A, B
-
-
50
µV/V
Stress above one or more of the limiting values may cause permanent damage to the device. Exposure to limiting values for extended
periods may affect device reliability.
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
4/9
MEASUREMENT CONDITIONS
Parameter
Symbol
Unit
Condition
Condition A: Set Up Conditions
Ambient temperature
T
°C
235
Measurement results are extrapolated to 25°C by using the
given temperature coefficients
Supply voltage
Vcc
V
5
Output voltage
VO
VO/Vcc
mV
mV/V
VO=(V0+ -V0- )
Output voltages are also given independently on supply
voltage: example: Vo/Vcc=(V0+ -V0- )/Vcc;
measure MR half bridge against reference half bridge
Reference half bridge
2* 2 k 0.1% (KMY21M only)
for full bridge sensors
(KMY20S, KMY20M, KMY22, KMZ20S, KMZ20M)
for half bridge sensors
(KMY 21 M)
The output voltage of the MR half bridge is measured
against a reference half bridge
Condition B: Sensor Specifications (T=25 °C, S-Type: Hx=3.00.5 kA/m)
Output voltage range
VO/Vcc
mV/V
min,max,
;/7...7OOOy VVVmkAH
Offset voltage
Voff/Vcc
mV/V
yOoffy HVVH ;0
Sensitivity
S
(mV/V)/(kA/m)
cc
yy
yV
HVHV
SmkAH
2
:;/1 00
Hysteresis
VH/Vcc
µV/V
Hy in kA/m
ccyy
yy
VHHV
HHV
/))11;0(
)11;0((
0
0
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
5/9
Y
X
Y
X
Condition C: Sensor Specifications (reference temperatures T=-25°C, +125°C)
Ambient temperatures
T
°C
T1=-25 °C, T0=+25 °C, T2=+125 °C
TC of amplitude
TCSV
%/K
%100
)(/ )(/)(/
)( 1
10
1020
12
TVV TVVTVV
TT
TCV
cc
cccc
TC of resistance
TCBR
%/K
%100
)( )()(
)( 1
1
12
12
TR TRTR
TT
TCR
TC of offset
TCVoff
(µV/V)/K
)( )()(
12
12 TT TVoffTVoff
TCVoff
SENSOR MODELS
KMY 20 / KMY 22 / KMZ 20
The KMY and KMZ sensors are highly sensitive magnetic field sensors which utilize the anisotropic magneto
resistance effect. The KMY 20 and KMZ 20 sensors contain a Wheatstone bridge.
Figure 3: Pad annotation and definition of field direction for KMY & KMZ
Y
X
+Vo +Vcc
GND -Vo
1 2 3 4
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
6/9
-15
-10
-5
0
5
10
15
-5 -4 -3 -2 -1 0 1 2 3 4 5
Field Strength Hy in kA/m
Output voltage in mV/V
Auxiliary field: Hx=3 kA/m
Figure 4: Characteristic
output curve of KMY 20
S resp. KMZ 20 S for an
auxiliary field strength of
Hx=3 kA/m
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
7/9
KMY 21
In contrast to the KMY20 sensor
products, the KMY 21 M consists of a
half bridge, making the sensor well
suited for dynamic measurements.
It contains an internal magnet, which
provides an auxiliary filed of approx.
2.5 kA/m.
Figure 5: Characteristic
curve for KMY21M
-6
-4
-2
0
2
4
6
-5 -4 -3 -2 -1 0 1 2 3 4 5
External Field Hy in kA/m
Output Voltage in mV/V
Auxiliary field: Hx=2.5 kA/m
TEMPERATURE DEPENDENCIES
0,4
0,6
0,8
1,0
1,2
1,4
-25 0 25 50 75 100 125
Temperature in °C
Vo(T)/Vo(+25°C) in %
Vo,min Vo(T)/Vo(+25°C) Vo,max
Figure 6: signal amplitude related to room temperature value
0,6
0,8
1,0
1,2
1,4
1,6
1,8
-25 0 25 50 75 100 125
Temperature in °C
Rb(T)/Rb(+25°C) in %
Rb,min Rb(T)/Rb(+25°C) Rb,max
Figure 7: bridge resistance related to room temperature value
Y
X
B
B
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
8/9
PACKAGES
SOT223
E-LINE 4 PIN
UTDFN8 2.5X2.8 MM
DIE
Die layout and dimensions on request.
Pin 1
The sensitive area is
positioned in the
center of the housing.
The bottom plate is designated to
be a heat sink. It has no electrical
connection to any pin.
.
Recommended solder reflow process for all packages
according to IPC/JEDEC J-STD-020D (Pb-Free Process)
KMY/KMZ Linear Magnetic Field Sensors
KMY/KMZ Rev 4 www.meas-spec.com 2012-December
9/9
ORDERING CODE
DEVICE
DIE
PACKAGE
INTERNAL MAGNET
PART NUMBER
KMY 20 S
full bridge
SOT-223
NO
G-MRCO-006
KMY 20 M
full bridge
SOT-223
YES
G-MRCO-001
KMY 21 M
half bridge
SOT-223
YES
G-MRCO-011
KMZ 20 S
full bridge
E-Line
NO
G-MRCO-007
KMZ 20 M
full bridge
E-Line
YES
G-MRCO-003
KMY 22
full bridge
UTDFN8
NO
on request
ORDERING INFORMATION
NORTH AMERICA
EUROPE
ASIA
Measurement Specialties, Inc.
1000 Lucas Way
Hampton, VA 23666
United States
Phone: +1-800-745-8008
Fax: +1-757-766-4297
Email: sales@meas-spec.com
Web: www.meas-spec.com
MEAS Deutschland GmbH
Hauert 13
D-44227 Dortmund
Germany
Phone: +49-(0)231-9740-0
Fax: +49-(0)231-9740-20
Email: info.de@meas-spec.com
Web: www.meas-spec.com
Measurement Specialties China Ltd.
No. 26, Langshan Road
High-tech Park (North)
Nanshan District, Shenzhen 518057
China
Phone: +86-755-33305088
Fax: +86-755-33305099
Email: info.cn@meas-spec.com
Web: www.meas-spec.com
The information in this sheet has been carefully reviewed and is believed to be accurate; however, no responsibility is assumed for
inaccuracies. Furthermore, this information does not convey to the purchaser of such devices any license under the patent rights to the
manufacturer. Measurement Specialties, Inc. reserves the right to make changes without further notice to any product herein.
Measurement Specialties, Inc. makes no warranty, representation or guarantee regarding the suitability of its product for any particular
purpose, nor does Measurement Specialties, Inc. assume any liability arising out of the application or use of any product or circuit and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters can and
do vary in different applications. All operating parameters must be validated for each customer application by customer’s technical
experts. Measurement Specialties, Inc. does not convey any license under its patent rights nor the rights of others.
