參數(shù)資料
型號: ADXL202E
廠商: Analog Devices, Inc.
元件分類: 圓形連接器
英文描述: Circular Connector; MIL SPEC:MIL-DTL-38999 Series I; Body Material:Metal; Series:LJT; No. of Contacts:11; Connector Shell Size:19; Connecting Termination:Crimp; Circular Shell Style:Wall Mount Receptacle; Body Style:Straight RoHS Compliant: No
中文描述: 低成本-2克雙軸加速度計輸出占空比
文件頁數(shù): 12/12頁
文件大?。?/td> 154K
代理商: ADXL202E
REV. A
–12–
C
P
ADXL202E
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
8-Terminal Ceramic Leadless Chip Carrier
(E-8)
BOTTOM VIEW
1
3
5
7
0.025
0.075
0.099
0.099
0.015 (0.38)
R(0.20)
0.015 (0.38)
0.050 (1.27)
0.197 (5.00)
SQ
0.177
(4.50)
SQ
TOP VIEW
R0.028 (0.70)
0.008
0.070 (1.78)
CONTROLLING DIMENSIONS ARE IN MILLIMETERS
0.050 (1.27)
0.050 (1.27)
USING THE ADXL202E IN VERY LOW POWER
APPLICATIONS
An application note outlining low power strategies for the
ADXL202E is available. Some key points are presented here.
It is possible to reduce the ADXL202E
s average current from
0.6 mA to less than 20
μ
A by using the following techniques:
1. Power Cycle the accelerometer.
2. Run the accelerometer at a Lower Voltage, (Down to 3 V).
Power Cycling with an External A/D
Depending on the value of the X
FILT
capacitor, the ADXL202E
is capable of turning on and giving a good reading in 1.6 ms. Most
microcontroller based A/Ds can acquire a reading in another 25
μ
s.
Thus it is possible to turn on the ADXL202E and take a reading
in <2 ms. If we assume that a 20 Hz sample rate is sufficient,
the total current required to take 20 samples is 2 ms
×
20 samples/s
×
0.6 mA = 24
μ
A average current. Running the part at 3 V will
reduce the supply current from 0.6 mA to 0.4 mA, bringing the
average current down to 16
μ
A.
The A/D should read the analog output of the ADXL202E at
the X
FILT
and Y
FILT
pins. A buffer amplifier is recommended, and
may be required in any case to amplify the analog output to give
enough resolution with an 8-bit to 10-bit converter.
Power Cycling When Using the Digital Output
An alternative is to run the microcontroller at a higher clock rate
and put it into shutdown between readings, allowing the use of the
digital output. In this approach the ADXL202E should be set at
its fastest sample rate (T2 = 0.5ms), with a 500 Hz filter at X
FILT
and Y
FILT
. The concept is to acquire a reading as quickly as pos-
sible and then shut down the ADXL202E and the microcontroller
until the next sample is needed.
In either of the above approaches, the ADXL202E can be turned
on and off directly using a digital port pin on the microcontroller to
power the accelerometer without additional components.
CALIBRATING THE ADXL202E/ADXL210
The initial value of the offset and scale factor for the ADXL202E
will require calibration for applications such as tilt measurement.
The ADXL202E architecture has been designed so that these
calibrations take place in the software of the microcontroller used
to decode the duty cycle signal. Calibration factors can be stored in
EEPROM or determined at turn-on and saved in dynamic
memory.
For low
g
applications, the force of gravity is the most stable,
accurate and convenient acceleration reference available. A reading
of the 0
g
point can be determined by orientating the device par-
allel to the earth
s surface and then reading the output.
A more accurate calibration method is to make measurements at
+1
g
and
1
g
. The sensitivity can be determined by the two
measurements.
To calibrate, the accelerometer
s measurement axis is pointed
directly at the earth. The 1
g
reading is saved and the sensor is
turned 180
°
to measure
1
g
. Using the two readings, the sensi-
tivity is:
Let A
=
Accelerometer output with axis oriented to
+1
g
Let B
=
Accelerometer output with axis oriented to
1
g
then
:
Sensitivity
= [A
B
]/2
g
For example, if the +1
g
reading (A) is 55% duty cycle and the
1
g
reading (B) is 32% duty cycle, then:
Sensitivity
= [55%
32%]/2
g
= 11.5%/
g
These equations apply whether the output is analog or duty cycle.
Application notes outlining algorithms for calculating accelera-
tion from duty cycle and automated calibration routines are
available from the factory.
相關(guān)PDF資料
PDF描述
ADXL202 Circular Connector; No. of Contacts:37; Series:LJTPQ00R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:15; Circular Contact Gender:Pin; Circular Shell Style:Wall Mount Receptacle
ADXL202AE Circular Connector; MIL SPEC:MIL-DTL-38999 Series I; Body Material:Metal; Series:LJT; No. of Contacts:5; Connector Shell Size:15; Connecting Termination:Crimp; Circular Shell Style:Wall Mount Receptacle; Body Style:Straight RoHS Compliant: No
ADXL202AQC Circular Connector; No. of Contacts:26; Series:LJTPQ00R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:17; Circular Contact Gender:Socket; Circular Shell Style:Wall Mount Receptacle
ADXL202JE Circular Connector; No. of Contacts:16; Series:LJTPQ00R; Body Material:Aluminum; Connecting Termination:Crimp; Connector Shell Size:21; Circular Contact Gender:Pin; Circular Shell Style:Wall Mount Receptacle
ADXL202JQC Circular Connector; MIL SPEC:MIL-DTL-38999 Series I; Body Material:Metal; Series:LJT; No. of Contacts:16; Connector Shell Size:21; Connecting Termination:Crimp; Circular Shell Style:Wall Mount Receptacle; Body Style:Straight RoHS Compliant: No
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADXL202EB 制造商:Analog Devices 功能描述:Evaluation Board For ADXL202 制造商:Analog Devices 功能描述:NO ADXL202 EVALUATION BOARD WITH LCC - Bulk 制造商:Analog Devices 功能描述:Special Function IC Supply Voltage Max.:
ADXL202EB-232 制造商:Analog Devices 功能描述:ADXL ACCEL EVAL BOARD
ADXL202EB-232 制造商:Analog Devices 功能描述:SEMICONDUCTOR ((NW))
ADXL202EB-232A 制造商:Analog Devices 功能描述:NO DUAL LOW G, LOW POWER ACCELEROMETER - Bulk
ADXL202JE 制造商:Analog Devices 功能描述:IC ACCELEROMETER 2 AXIS 2G LCC8