KMT36H 360° Angular Sensor
KMT36H Rev 5 www.meas-spec.com 2013-April
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• AMR Sensor with 360° capability
• TDFN outline 2.5x2.5x0.75 mm3
• Three 120° phase-shifted signals
• Moderate field strength requirements
DESCRIPTION
The KMT36H is a magnetic field sensor utilizing the anisotropic m agneto resist ance effect. Therefore
the sensor is sens in g the m agnetic field direction rather than the magnetic field strength. T he s ens or
contains three W heats tone bridges rotate d by 120°. A rotati ng m agnetic fiel d (t ypical strength 25 kA/m
in the sens or pl ane) will result in thr e e s inuso id al o utpu t signa ls with a per iod of 18 0°, phase shifted by
60° field angle. By use of a modified atan algorithm the field angle can be calculated with high
accuracy.
As an u niq ue f eatur e, the K MT36H is able t o measure f ull 3 60° by utilizing an ad di t ion al magnetic fiel d
which is generated b y a planar coil that is integrated on the ch ip. T he 180°/3 60° d eterm ination is done
by a simple sign distinction and may be computed periodically or only once at power up.
FEATURES APPLICATIONS
• Ideal for harsh environments due to
magnetic sensing principle
• Absolute angle measurement
• Contactless absolute angular measurement
over 360°
• Potentiometer replacement
• Accuracy better than +/- 0.5° • Motor motion control
• Three bridge signals with 120° phase
difference
• Camera positioning
• Tiny TDFN-housing 2.5 x 2.5 x 0.8 mm
3
• Robotics
KMT36H 360° Angular Sensor
KMT36H Rev 5 www.meas-spec.com 2013-April
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CHARACTERISTIC VALUES
Parameter Condition Symbol Min Typ Max Unit
Mechanical dimensions - TDFN
Length X 2.5 mm
Width Y 2.5 mm
Height Z 0.75 mm
Mechanical dimensions - SO8
Length X 4.9 mm
Width Y 6.0 mm
Height Z 1.75 mm
Operating limits
Supply voltage VCC 5 12 V
Coil current T = 25 °C, H = 25 kA/m ICOIL 20 50 mA
Operating temperature -40 +125 °C
Storage temperature -40 +125 °C
Parameter Condition Symbol Min Typ Max Unit
Sensor specification
Applied magnetic field 2), 3) H 15 25 60 kA/m
Bridge resistance T = 25 °C RB 2.4 3.0 3.6 kΩ
max. signal range T = 25 °C, H = 25 kA/m ∆V/VCC 18 22 26 mV/V
Offset voltage 4) T = 25 °C VOFF/VCC -3 +3 mV/V
Hysteresis 1)
(Repeatability) H = 25 kA/m Hyst 0.15 0.30 deg
Accuracy 1) H = 25 kA/m ∆α 0.15 0.30 deg
TC of amplitude H = 25 kA/m, 5) TCAMP -0.32 %/K
TC of bridge resistance 5) TCR +0.32 %/K
Coil resistance T = 25 °C RCOIL 75 100 150 Ω
Thermal resistance
(junction-ambient) Tamb = 25°C, 6) RthJ/A 280 K/W
1) Hysteresis and acc uracy are depending nearly i nvers el y proporti onal on the magnetic field strength. The accuracy is def i ned
as the max. angular difference between actual fiel d angle and measured angle calculated from the third and fifth harmonics
of the Fourier spectrum. The hysteresis is defined as angular di fference bet ween left and ri ght t urn.
2) Generated with reference magnet 67.044 Magnetfabrik Bonn (25 kA/m @ 5.2 mm distance).
3) Minimum value depends on decreasing accuracy, upper limit on decreasing coil i nfluence. Both are no absolute l imits, but
depend on the given application requirements.
4) Offset voltages measured as difference volt ages VO1-VO2, VO2-VO3 and VO3-VO1 in relation to VCC.
5) Reference temperature Tref = -25 °C, calculated f rom values at -25°C and +125 °C
6) TDFN soldered on standard test PCB, heat sink without solder connection
KMT36H 360° Angular Sensor
KMT36H Rev 5 www.meas-spec.com 2013-April
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BLOCK DIAGR AM
Figure 1: internal and external connections (TDFN and SO8, Chip)
SENSOR OUTLINE
Figure 2: SO8 outline
The sensitive area is
positioned in the center of
the housing.
VO1
VO3
VO2
VCC
GND
n. c.
VCOIL-
VCOIL+
1
5
8
4
KMT36H 360° Angular Sensor
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Figure 3: TDFN outline
Pin Assignment for TDFN and SO8: Recommended Solder Layout for TDFN:
Pin Symbol Function
1 VO2 signal output 2
2 GND negative supply voltage
3 VCC positive supply voltage
4 VO1 signal output 1
5 VCOIL+ positive coil inp ut
6 n. c. not connected
7 VCOIL- negative coil input
8 VO3 signal output 3
Recommended solder reflow process according to IPC/JEDEC J-STD-020D (Pb-Free Process)
TAPE AND REEL PACKAGING INFORMATION
DESCRIPTION REEL SIZE UNITS/REEL PIN 1 ORIENTATION NOTE
KMT36H 7” 3,000 Top-right of sprocket hole
side
KMT36H/SO 13” 2,500 Top-left of sprocket hole
side
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.
KMT36H 360° Angular Sensor
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TYPICAL PERFORMANCE CURVES
Figure 3: output voltages
Figure 4: output voltage change due to coil influence
SIGNAL EVALUATION
180° EVALUATION
As output vo ltages (V1, V2, V3) we us e the three poss ible diff erences betwe en the three sign al outputs
(see fig. 3). At first the true offsets must be subtracted from the raw signals. The field angle α in a
180°-range then can be calculated in the following manner:
Using the three possible combinations of output signals (m,n = 1,2 ; 2,3 ; 3,1) three results are
obtained, which can be averaged to increase accuracy. Comparing the three results gives additional
information about their reliability.
360° EVALUATION
In order to distinguish between α and α+180° two additional measurements are needed: one with
positive, the other with negative coil current. In the next step the change in the signals due to the
influenc e of the c oil curr ent m ust be calc ulated . The s ign of thes e coil -induce d out put voltag e chan ges
gives the 360°-information by case differentiation (see figure 4). In principle, this 360° discrimination
needs to be computed only once at start up. Nevertheless, it is recommended to check the
measurement periodically.
+⋅
⋅= 3
12
arctan
2
1Vm
Vn
α
090 180 270 360
field angle in d eg
V1 = Vo2-Vo1 V2 = Vo3-Vo2 V3 = Vo1-Vo3
090 180 270 360
field angle in d eg
V1(+Icoil) - V1(-Icoil) V2(+Icoil) - V2(-Icoil)
V3(+Icoil) - V3(-Icoil)
KMT36H 360° Angular Sensor
KMT36H Rev 5 www.meas-spec.com 2013-April
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APPLICATION EXAMPL E
Figure 5: An exemplary hardware configuration using an Atmel ATtiny44 microcontroller
ORDERING CO DE
ORDERING INFORMATION
NORTH AMERICA
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Measurement Specialties, Inc.
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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
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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.
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High-tech Park (North)
Nanshan District, Shenzhen 518057
China
Phone: +8 6 -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 suc h 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. m akes no warranty, represent ation or guarantee regarding t he suitability of it s product for any partic ular
purpose, nor does Measurem ent Specialties, Inc. assume any liability aris ing out of t he application or use of any product or c ircuit and
specifically disclaims any and all liability, including without limitati on 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.
DEVICE PACKAGE MOQ PART NUMBER
KMT36H TDFN 2.5 x 2.5 1 Reel G-MRCO-021
KMT36H/SO SO8 (References: JEDEC MS-012) 1 Reel on request
