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MT6803 Magnetic Angle Sensor IC
www.magntek.de 1/ 10 Rev 1.0 10/2016
Features and Benefits
Based on advanced magnetic field
sensing technology
Measures magnetic field direction rather
than field intensity
Contactless angle measurement
Large air gap
Excellent accuracy, even for weak
magnetic field
Position tolerant
Negligible hysteresis
Single chip solution
RoHS Compliant 2011/65/EU
Applications
Contactless potentiometer
Steering angle sensor for EPS
Servo motor control
General Description
The MagnTek rotary position sensor MT6803 is an IC based on advanced magnetic field sensing
technology. The sensor contains two Wheatstone bridges formed by a magnet field sensing element
array. A rotating magnetic field in the x-y sensor plane delivers two sinusoidal output signals indicating
the angle (α) between the sensor and the magnetic field direction. Within a homogeneous field in the x-y
plane, the output signals are relatively independent of the physical placement in the z direction (air gap).
The sensor is only sensitive to the magnetic field direction as the sensing element output is specially
designed to be independent from the magnet field strength. This allows the device to be less sensitive to
magnet variations, stray magnetic fields, air gap changes and off-axis misalignment.
This contactless system measures the absolute angle of a diametrically magnetized on-axis magnet. It is
especially suitable for applications such as contactless potentiometer, EPS steering angle sensor, etc.
MT6803 Magnetic Angle Sensor IC
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Pin Configuration
Figure 1: Pin Configuration for SOP-8 Package
(Also showing sensor element center location, zero degree position and angle rotation direction)
Name Number Type Description
MODE 1 Digital input Set to logic low in normal operation; Set to logic
high in I2C mode.
NSP 2 Digital input External magnetic switch input for 360 detection
AOUT 3 Analog output Linear voltage output
VDD 4 Supply 5V supply
GND 5 Ground Ground
HVPP 6 Supply 7.5V supply only needed for NVM programming.
NC for normal operation.
SCL 7 Digital I/O I2C clock
SDA 8 Digital I/O I2C data
Family Members
※ MTT6803CT is qualified for automotive applications.
Part number Description
MT6803CT SOP-8 package, tubes packaging (3000pcs/bag)
MTT6803CT※ SOP-8 package, tubes packaging (3000pcs/bag)
MT6803 Magnetic Angle Sensor IC
www.magntek.de 3/ 10 Rev 1.0 10/2016
Functional Description
The MT6803 is manufactured in a CMOS standard process and uses advanced magnet sensing
technology to sense the magnetic field distribution across the surface of the chip. The integrated
magnetic sensing element array delivers a voltage representation of the magnetic field at the surface of
the IC.
A small low cost diametrically magnetized (two-pole) standard magnet can be used to provide angular
position information. The MT6803 senses the orientation of the magnetic field and generates linear
outputs as depicted in Figure 3. The output voltage amplitude is ratiometric to the supply voltage.
Figure 2: Simplified System Block Diagram
Figure 3: Typical Output Waveform (Magnet rotates in clock-wise direction)
0%
20%
40%
60%
80%
100%
0 30 60 90 120 150 180 210 240 270 300 330 360
Output Voltage (%VDD)
Angle (deg)
Figure 2 shows a simplified block diagram of the chip, consisting of the magnetic sensing element
realized by two interleaved Wheatstone bridges to generate cosine and sine signals, gain stages,
analog-to-digital converters (ADC) for signal conditioning, a digital signal processing (DSP) unit for angle
calculation and digital-to-analog convert (DAC) to generate linear voltage output. Other supporting
blocks such as LDO, NVM, I2C, etc. are also included.
MT6803 Magnetic Angle Sensor IC
www.magntek.de 4/ 10 Rev 1.0 10/2016
Absolute Maximum Ratings (Non-Operating)
Stresses beyond those listed under “Absolute Maximum Ratings “may cause permanent damage to the
device. These are stress ratings only. Functional operation of the device at these or any other conditions
beyond those indicated under “Operating Conditions” is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
Parameter Notes Min Max Unit
DC voltage at pin VDD - -0.3 8 V
DC voltage at pin HVPP - -0.3 8 V
Storage temperature - -55 160 °C
Operating Temperature MT6803 -40 85 °C
MTT6803 -40 150 °C
Electrostatic discharge
(HBM)
MT6803 - ±2 kV
MTT6803 - ±4 kV
Electrical Characteristics
Operating conditions: Ta= -40 to +150°C, VDD= 3.0-5.5V unless otherwise noted.
Symbol Parameter Conditions/Notes Min Typ Max Unit
VDD Supply Voltage - 3.0 5 5.5 V
HVPP Supply Voltage - 7.25 7.5 7.75 V
Idd Supply Current - - 3.0 4.0 mA
Sens Sensitivity Programmable - 0.44 - %VDD/°
Vsathi Output Saturation
Voltage High Programmable - 90 - %VDD
Vsatlo Output Saturation
Voltage Low Programmable - 10 - %VDD
LSB Analog Output
Resolution 10-bit DAC - 0.078 - %VDD
INL Integral Non-Linearity Note (1) - ±1.0 ±2.0 Degrees
Anoi Output Noise
Ta=25°C, VDD=3.3V,
RMS value, excluding
DAC quantization noise
- 0.02 - %VDD
Erm Ratiometric Error Note (2) -0.3 - 0.3 %
TPwrUp Power-up time - - - 1.1 ms
Tdelay Propagation delay - - - 0.5 ms
Analog Output Characteristics
Rout Output Resistance - - - 10 Ω
RL Output Load
Pull-up or pull-down 1 - - kΩ
CL - - - 500 pF
I2C IO Characteristics
MT6803 Magnetic Angle Sensor IC
www.magntek.de 5/ 10 Rev 1.0 10/2016
VIH High level input voltage - VDD-1 - - V
VIL Low level input voltage - - - 0.8 V
VSON Open Drain Output
Saturation Voltage Iout = 3.3 mA - - 0.4 V
ILK Input Leakage Current - - - ±1 μA
I2C Timing Specification
Fscl SCL Clock - 100 400 kHz
tlow SCL Low Period - 1 - - μs
thigh SCL High Period - 1 - - μs
tsudat SDA Setup Time - 0.1 - - μs
thddat SDA Hold Time - 0 - 0.9 μs
thdsta Start Hold Time - 0.6 - - μs
tsusta Start Setup Time - 0.6 - - μs
tsusto Stop Setup Time - 0.6 - - μs
tbuf New Transmission
Time - 1.3 - - μs
Notes:
1. The typical error value can be achieved at room temperature and with no off-axis misalignment error.
The max error value can be achieved over operation temperature range, at maximum air gap and
with worst-case off-axis misalignment error.
2. The analog output is by design ratiometric, i.e. it is proportional to the supply voltage VDD. The
ratiometric error is calculated as follows.
Erm5V
5∙ 100%
Magnetic Input Specification
Operating conditions: Ta= -40 to +150°C, VDD= 3.3-5.5V unless otherwisenoted. Two-pole cylindrical
diametrically magnetized source.
Symbol Parameter Notes Min Typ Max Unit
Dmag Diameter
Recommended magnet:
Ø8mm x 2.5mm for
cylindrical magnets
- 8 - mm
Tmag Thickness - - 2.5 - mm
Bpk Magnetic input field
amplitude Measured at the IC surface. 300 - 3000 Gauss
AG Air Gap Magnet to IC surface
distance (Figure4). 1.0 - 3.0 mm
RS Rotation Speed - - - 10 KRPM
DISP Off-Axis
Misalignment
Misalignment error between
sensor center and magnet - - 0.3 mm
MT6803 Magnetic Angle Sensor IC
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axis (Figure4).
TCmag1 Recommended
magnet material
and
temperature drift
NdFeB (Neodymium Iron
Boron) - -0.12 -
%/°C
TCmag2 SmCo (Samarium Cobalt) - -0.035 -
Figure4: Magnet Arrangement
I2C Operation
Alternative to the linear voltage output, the MT6803 also provides an I2C interface for host IC to read back
angle information from its internal registers listed below. The slave address of the device is 0000110 in 7-bit
binary form. The read/write protocol is explained in details in this section.
Address Description
0x03 Angle_Readback<7:0>
0x04 Angle_Readback<15:8>
Figure 5: I2C Timing Diagram
Abbreviation
SACK Acknowledged by slave
MACK Acknowledged by master
NACK Not acknowledged by master
RW Read/Write
MT6803 Magnetic Angle Sensor IC
www.magntek.de 7/ 10 Rev 1.0 10/2016
Start/Stop/Ack
START: Data transmission begins with a high to transition on SDA while SCL is held high. Once I2C
transmission starts, the bus is considered busy.
STOP: STOP condition is a low to high transition on SDA line while SCL is held high.
ACK: Each byte of data transferred must be acknowledged. The transmitter must release the SDA line
during the acknowledge pulse while the receiver mush then pull the SDA line low so that it remains
stable low during the high period of the acknowledge clock cycle.
NACK: If the receiver doesn’t pull down the SDA line during the high period of the acknowledge clock
cycle, it’s recognized as NACK by the transmitter.
I2C Write I2C write sequence begins with start condition generated by master followed by 7 bits slave address and
a write bit (R/W=0). The slave sends an acknowledge bit (ACK=0) and releases the bus. The master
sends the one byte register address. The slave again acknowledges the transmission and waits for 8 bits
data which shall be written to the specified register address. After the slave acknowledges the data byte,
the master generates a stop signal and terminates the writing protocol.
STA
RT
Slave Address R
W
SA
CK
Register Address
(0x09)
SA
CK
Data
(0x01)
SA
CK
ST
OP
0 0 0 0 1 1 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 1
I2C Read
I2C write sequence consists of a one-byte I2C write phase followed by the I2C read phase. A start
condition must be generated between two phase. The I2C write phase addresses the slave and sends
the register address to be read. After slave acknowledges the transmission, the master generates again
a start condition and sends the slave address together with a read bit (R/W=1). Then master releases
the bus and waits for the data bytes to be read out from slave. After each data byte the master has to
generate an acknowledge bit (ACK = 0) to enable further data transfer. A NACK from the master stops
the data being transferred from the slave. The slave releases the bus so that the master can generate a
STOP condition and terminate the transmission.
The register address is automatically incremented and more than one byte can be sequentially read out.
Once a new data read transmission starts, the start address will be set to the register address specified
in the current I2C write command.
MT6803 Magnetic Angle Sensor IC
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STA
RT
Slave Address R
W
SA
CK
Register Address
(0x00)
SA
CK
0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0
STA
RT
Slave Address R
W
SA
CK
Data
(0x00)
MA
CK
Data
(0x01)
0 0 0 0 1 1 0 1 D D D D D D D D D D D D D D D D
MA
CK
Data
(0x02)
MA
CK
………………………
……….
MA
CK
Data
(0x07)
NA
CK
ST
OP
D D D D D D D D ………………………
……….
D D D D D D D D
Application Information
Reference Circuit Figure 6 shows a reference circuit for typical applications that use the analog output. For applications
that use I2C interface to obtain angle information, the reference circuit in Figure 7 is recommended. For
harsh working environment, it is recommended to add filtering (e.g. ferrite beads) and protection circuit
(e.g. TVS) to the supply.
Figure 6: Reference Application Circuit for Analog Interface
MT6803 Magnetic Angle Sensor IC
www.magntek.de 9/ 10 Rev 1.0 10/2016
Figure 7: Reference Application Circuit for I2C Interface
Magnet Selection and Placement
It is recommended that the magnetic field density at the chip surface reach 300 Gauss to guarantee that
the magnetic sensing elements operate in saturation mode to ensure good linearity. Please be noted that
the sensing element in the chip is not at the package center, rather it is aligned with PIN 3 and 6 edges
(see the figures in the “Package Information” section). It is required that the magnet’s center axis be
aligned with the sensing element center. Any misalignment introduces additional angle error. Magnets
with larger radius are more tolerant to off-axis misalignment. It also allows the magnet to be placed at the
large air gap distance from the chip. 360 Degree Detection
By default, MT6803 does not distinguish north and south pole, which makes its output have a period of
180 degrees. To enable 360 degree detection, it is possible to add external magnetic switch sensor
devices such as Hall or GMR sensor to help it distinguish north and south pole. For details, please refer
to application note AN001.
Programming
MT6803 can be programmed through dedicated programmer PB02 with its companion GUI software.
The following parameters can be programmed: start angle, stop angle, sensitivity, output saturation
(clamp) voltage, optional external magnetic switch sensor input, etc.
MT6803 Magnetic Angle Sensor IC
www.magntek.de 10/ 10 Rev 1.0 10/2016
PACKAGE DESIGNATOR
(MT6803CT) SOP-8
A
A1
A2
D
b
E1
E
e
c
L
ɗ
L1
L1'
Symbol Dimensions in Millimeters Dimensions in Inches
Min Max Min Max
A 1.595 1.775 0.063 0.070
A1 0.050 0.150 0.002 0.006
A2 1.350 1.550 0.053 0.061
b 0.375 0.425 0.015 0.017
c 0.170 0.250 0.007 0.010
D 4.700 5.100 0.185 0.200
E 3.875 3.925 0.153 0.155
E1 5.800 6.200 0.228 0.244
e 1.270(BSC) 0.050(BSC)
L 0.615 0.765 0.024 0.030
L1 1.040REF 0.041REF
L1-L1’ - 0.120 - 0.005
y 1.900 1.950 0.075 0.077
z 0.526 0.609 0.021 0.024
θ 0˚ 8˚ 0˚ 8˚
x 0.860 0.034