MXC62020MP MEMSIC, MXC62020MP Datasheet - Page 8

• Manufacturer Part Number: MXC62020MP
• Description: ACCELEROMETER, 2 AXIS, ±2.0G, I2C
• Manufacturer: MEMSIC

Specifications of MXC62020MP

• No. Of Axes: 2
• Sensor Case Style: LCC
• No. Of Pins: 8
• Supply Voltage Range: 2.7V To 3.6V
• Operating Temperature Range: -40°C To +85°C
• Operating Temperature Max: 85°C
• Operating: RoHS Compliant
• Acceleration Range: ±2g

RESOLUTION
The accelerometer resolution is limited by noise. The
output noise will vary with the measurement bandwidth.
With the reduction of the bandwidth, by applying an
external low pass filter, the output noise drops. Reduction
of bandwidth will improve the signal to noise ratio and the
resolution. The output noise scales directly with the square
root of the measurement bandwidth. The maximum
amplitude of the noise, its peak- to- peak value,
approximately defines the worst case resolution of the
measurement. With a simple RC low pass filter, the rms
noise is calculated as follows:
Noise (mg rms) = Noise(mg/ Hz ) *
The peak-to-peak noise is approximately equal to 6.6 times
the rms value (for an average uncertainty of 0.1%).
HARDWARE DESIGN CONSIDERATION
1. One capacitor is recommended for best rejection of
2. Robust low inductance ground wiring should be used.
3. Care should be taken to ensure there is “thermal
4. A metal ground plane should be added directly beneath
5. Vias can be added symmetrically around the ground
MEMSIC MXC6202xG/H/M/N
Power supply noise rejection
power supply noise (reference figure below). The
capacitor should be located as close as possible to the
device supply pin (V
should be as short as possible, and a surface mount
capacitor is preferred. For typical applications, the
capacitor can be ceramic 0.1 µF.
symmetry” on the PCB immediately surrounding the
MEMSIC device and that there is no significant heat
source nearby. Based on the experiment, with a
120degC heating source at 11mm away of MEMSIC
device, the offset change will be within 5mg.
the MEMSIC device. The size of the plane should be
similar to the MEMSIC device’s footprint and be as
thick as possible.
plane. These vias will increase the thermal isolation of
the device from the rest of the PCB and improve
performance.
DD
). The capacitor lead length
Rev.C
(
Bandwidth
(
Hz
* )
. 1
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SOFTWARE DESIGN CONSIDERATION
In order to further reduce the noise on the I2C bus, we
recommend to use the following software limiter filter in
the acceleration signal process routine:
Int iAccReal[0x02];//Real-time acceleration data array
Int iAccFilter;//Filtered acceleration data
SoftwareLimiterFilter()
{
if (abs(iAccReal[0x00]-iAccReal[0x01])<0x80) then
iAccFilter=iAccReal[0x00];
iAccReal[0x01]= iAccReal[0x00];
}
I
A slave mode I
Memsic thermal accelerometer as a standard interface for
customer applications. The A/D converter and MCU
functionality have been added to the Memsic sensor,
thereby increasing ease-of-use, and lowering power
consumption, footprint and total solution cost.
The I
directional two-wire interface bus. A master I
operate READ/WRITE controls to an unlimited number of
devices on the bus by proper addressing. The Memsic
accelerometer operates only in a slave mode, i.e. only
responding to calls by a master device
I
The two wires in I
and SCL (serial clock line). In order for a data transfer to
start, the bus has to be free, which is defined by both wires
in a HIGH output state. Due to the open-drain/pull-up
resistor structure and wire-AND operation, any device on
the bus can pull lines low and overwrite a HIGH signal.
The data on the SDA line has to be stable during the HIGH
period of the SCL line. In other words, valid data can only
change when the SCL line is LOW.
2
2
C INTERFACE DESCRIPTION
C BUS CHARACTERISTICS
2
C (or Inter IC bus) is an industry standard bi-
2
C circuit has been implemented into the
2
C bus are called SDA (serial data line)
I
2
C bus
2
C device can
2
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