1. Introduction of MEMSIC Magnetic Sensor Solution

2. MEMSIC Confidential Property
Agenda
Background Knowledge
MEMSIC Magnetic Sensor Solution
Advantage of MEMSIC Magnetic Sensor Application Solution (Cellphone)
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3. Background Knowledge

4. MEMSIC Confidential Property
The Magnetic Effect
Magnetic, a basic physical effect
Magnetic field can be generated by magnet or electrical circuit.
Magnetic field directs from Magnetic North to South.
Like magnet repel each other, unlike magnet attract.
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5. Earth’s Geomagnetic Field
General Earth’s Surface: H= 48 A/m (0.6 Oe) B = 0.6 x 10-4 Tesla (0.6 Gauss)
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6. Geomagnetic Field & Compass for Orientation
Geomagnetic field behaves like there is a big “magnet” inside the earth.
Geomagnetic north pole is near earth’s South pole, geomagnetic south pole is near earth’s north pole.
Compass is a small piece of magnet, attracted by geomagnetic field. Mag north heads earth’s north, mag south heads south.
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7. How to feel/detect Geomagnetic Field
Traditional mechanical Compass & related tools
Electronics devices, MEMS Sensor technology
Traditional mechanical tools
New MEMS sensor technology
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8. Geomagnetic Inclination & Orientation Projection
Geomagnetic field is not constant all around the world, and normally neither vertical nor horizontal.
Northern Hemisphere the field points DOWN, Southern Hemisphere the field points UP, quarter is almost vertical.
A 3D Mag sensor is measuring the 3D vector geomagnetic filed, need be projected to a 2D vector in the ground plane to indicate the orientation.
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9. MEMSIC Magnetic sensor Technology

10. MEMSIC Magnetic Sensor
Based on Anisotropic Magneto-Resistive (AMR) technology
Fully integrated sensors with minimal external components
Measures full range of ±4 gausses
Linear biasing
Small, low-profile packaging
Power up/down function available through I2C interface
13 bit ADC, 512 counts/gauss resolution (2mGauss/LSB)
I2C Slave, FAST (≤400 KHz) mode
Low Power Consumption
MMC314x Tri-axis Magnetic Sensor: Typically with 50 measurements per second
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11. MEMSIC Magnetic Sensor
MMC314x
Tri-Axis Magnetic Sensor
I2C Interface
+/- 4Gauss Measurement Range
3x3x1 mm package
MMC214x
Dual-Axis Magnetic Sensor
3x3x0.7 mm package

12. MEMSIC Magnetic Sensor
Current only applies when taking measurement, thus lower current consumption. (0.01mA/Measurement)
Magnetization coil to re-direct magnetization to maintain directionality over time, as well as good zero-point offset.
High accuracy due to Wheatstone bridge resistance change. (512DAC/Gauss, 2mGauss Resolution)
High sensitivity even across temperature change.
The reaction of the magneto resistive effect is very fast (7mS/Measurement)
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13. AMR: Anisotropic Magneto Resistive
Resistivity changes as a function of the angle between the current generated magnetized field direction and the external magnetic field.
Apply current ONLY when you need to measure external magnetic field.
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14. Measurement Range of Magnetic Sensor Technology
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