- 您現在的位置：買賣IC網 > PDF目錄374048 > ADXL202E (Analog Devices, Inc.) 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 PDF資料下載
參數資料
| 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： | 11/12頁 |
| 文件大?。?/td> | 154K |
| 代理商： | ADXL202E |
REV. A
ADXL202E
–11–
A DUAL AXIS TILT SENSOR: CONVERTING
ACCELERATION TO TILT
When the accelerometer is oriented so both its X and Y axes are
parallel to the earth
’
s surface it can be used as a two axis tilt sensor
with a roll and a pitch axis. Once the output signal from the
accelerometer has been converted to an acceleration that varies
between
–
1
g
and +1
g,
the output tilt in degrees is calculated as
follows:
Pitch
=
ASIN
(
Ax
/1
g
)
Roll
=
ASIN
(
Ay
/1
g
)
Be sure to account for overranges. It is possible for the acceler-
ometers to output a signal greater than
±
1
g
due to vibration,
shock or other accelerations.
MEASURING 360 OF TILT
It is possible to measure a full 360
°
of orientation through gravity
by using two accelerometers oriented perpendicular to one another
(see Figure 5). When one sensor is reading a maximum change
in output per degree, the other is at its minimum.
360
OF TILT
1
g
Y
X
Figure 5. Using a Two-Axis Accelerometer to Measure
360
°
of Tilt
USING THE ANALOG OUTPUT
The ADXL202E was specifically designed for use with its digital
outputs, but has provisions to provide analog outputs as well.
Duty Cycle Filtering
An analog output can be reconstructed by filtering the duty cycle
output. This technique requires only passive components. The
duty cycle period (T2) should be set to <1 ms. An RC filter with a
3 dB point at least a factor of >10 less than the duty cycle fre-
quency is connected to the duty cycle output. The filter resistor
should be no less than 100 k
to prevent loading of the output
stage. The analog output signal will be ratiometric to the supply
voltage. The advantage of this method is an output scale factor of
approximately double the analog output. Its disadvantage is that
the frequency response will be lower than when using the X
FILT
,
Y
FILT
output.
X
FILT
, Y
FILT
Output
The second method is to use the analog output present at the
X
FILT
and Y
FILT
pin. Unfortunately, these pins have a 32 k
output impedance and are not designed to drive a load directly.
An op amp follower may be required to buffer this pin. The
advantage of this method is that the full 5 kHz bandwidth of the
accelerometer is available to the user. A capacitor still must be
added at this point for filtering. The duty cycle converter should
be kept running by using R
SET
<10 M
. Note that the acceler-
ometer offset and sensitivity are ratiometric to the supply voltage.
The offset and sensitivity are nominally:
0
g
Offset = V
DD
/2
ADXL202E Sensitivity = (60 mV
×
V
S
)/
g
Table V. Trade-Offs Between Microcontroller Counter Rate,
T2 Period, and Resolution of Duty Cycle Modulator
Counter-
ADXL202E Clock
R
SET
Sample
T2 (ms) (k ) Rate
Counts
per T2
Cycle
Rate
(MHz)
Counts Resolution
per
g
(m
g
)
1.0
1.0
1.0
5.0
5.0
5.0
10.0
10.0
10.0
124
124
124
625
625
625
1250 100
1250 100
1250 100
1000
1000
1000
200
200
200
2.0
1.0
0.5
2.0
1.0
0.5
2.0
1.0
0.5
2000
1000
500
10000
5000
2500
20000
10000
5000
250
125
62.5
1250
625
312.5
2500
1250
625
4.0
8.0
16.0
0.8
1.6
3.2
0.4
0.8
1.6
STRATEGIES FOR USING THE DUTY CYCLE OUTPUT
WITH MICROCONTROLLERS
Application notes outlining various strategies for using the duty
cycle output with low cost microcontrollers are available from
the factory.
USING THE ADXL202E AS A DUAL-AXIS TILT SENSOR
One of the most popular applications of the ADXL202E is tilt
measurement. An accelerometer uses the force of gravity as an
input vector to determine orientation of an object in space.
An accelerometer is most sensitive to tilt when its sensitive axis
is perpendicular to the force of gravity, i.e., parallel to the earth
’
s
surface. At this orientation its sensitivity to changes in tilt is high-
est. When the accelerometer is oriented on axis to gravity, i.e.,
near its +1
g
or
–
1
g
reading, the change in output acceleration
per degree of tilt is negligible. When the accelerometer is perpen-
dicular to gravity, its output will change nearly 17.5 m
g
per degree
of tilt, but at 45
°
degrees it is changing only at 12.2 m
g
per
degree and resolution declines. The following table illustrates
the changes in the X and Y axes as the device is tilted
±
90
°
through gravity.
Y
X
+90
0
–
90
1
g
X Output
Y Output (
g
)
X Axis
Orientation
to Horizon ( )
per
Degree of
Tilt (m
g
)
per
Degree of
Tilt (m
g
)
X Output (
g
)
Y Output (
g
)
–
90
–
75
–
60
–
45
–
30
–
15
–
1.000
–
0.966
–
0.866
–
0.707
–
0.500
–
0.259
0.000
0.259
0.500
0.707
0.866
0.966
1.000
–
0.2
4.4
8.6
12.2
15.0
16.8
17.5
16.9
15.2
12.4
8.9
4.7
0.2
0.000
0.259
0.500
0.707
0.866
0.966
1.000
0.966
0.866
0.707
0.500
0.259
0.000
17.5
16.9
15.2
12.4
8.9
4.7
0.2
–
4.4
–
8.6
–
12.2
–
15.0
–
16.8
–
17.5
0
15
30
45
60
75
90
BOTTOM VIEW
Figure 4. How the X and Y Axes Respond to Changes
in Tilt
相關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 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| 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 |
發布緊急采購，3分鐘左右您將得到回復。