Zakładka z wyszukiwarką danych komponentów
Selected language     Polish  ▼
Nazwa części
         Szczegóły


ADXL335 Datasheet(Arkusz danych) 7 Page - Analog Devices

Numer części ADXL335
Szczegółowy opis  Small, Low Power, 3-Axis ±3 g Accelerometer
Pobierz  11 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Producent  AD [Analog Devices]
Strona internetowa  http://www.analog.com
Logo 

 
 7 page
background image
Preliminary Technical Data
ADXL335
Rev. PrA | Page 7 of 11
APPLICATIONS
POWER SUPPLY DECOUPLING
For most applications, a single 0.1 μF capacitor, CDC, placed
close to the ADXL335 supply pins adequately decouples the
accelerometer from noise on the power supply. However, in
applications where noise is present at the 50 kHz internal clock
frequency (or any harmonic thereof), additional care in power
supply bypassing is required as this noise can cause errors in
acceleration measurement. If additional decoupling is needed,
a 100 Ω (or smaller) resistor or ferrite bead can be inserted in
the supply line. Additionally, a larger bulk bypass capacitor
(1 μF or greater) can be added in parallel to CDC. Ensure that
the connection from the ADXL335 ground to the power supply
ground is low impedance because noise transmitted through
ground has a similar effect as noise transmitted through VS.
SETTING THE BANDWIDTH USING CX, CY, AND CZ
The ADXL335 has provisions for band limiting the XOUT, YOUT,
and ZOUT pins. Capacitors must be added at these pins to
implement low-pass filtering for antialiasing and noise
reduction. The equation for the 3 dB bandwidth is
F−3 dB = 1/(2π(32 kΩ) × C(X, Y, Z))
or more simply
F–3 dB = 5 μF/C(X, Y, Z)
The tolerance of the internal resistor (RFILT) typically varies as
much as ±15% of its nominal value (32 kΩ), and the bandwidth
varies accordingly. A minimum capacitance of 0.0047 μF for CX,
CY, and CZ is recommended in all cases.
Table 5. Filter Capacitor Selection, CX, CY, and CZ
Bandwidth (Hz)
Capacitor (μF)
1
4.7
10
0.47
50
0.10
100
0.05
200
0.027
500
0.01
SELF TEST
The ST pin controls the self test feature. When this pin is set to
VS, an electrostatic force is exerted on the accelerometer beam.
The resulting movement of the beam allows the user to test if
the accelerometer is functional. The typical change in output is
−500 mg (corresponding to −150 mV) in the X-axis, 500 mg (or
150 mV) on the Y-axis, and −200 mg (or −60 mV) on the Z-axis.
This ST pin may be left open circuit or connected to common
(COM) in normal use.
Never expose the ST pin to voltages greater than VS + 0.3 V. If
this cannot be guaranteed due to the system design (for
instance, if there are multiple supply voltages), then a low VF
clamping diode between ST and VS is recommended.
DESIGN TRADE-OFFS FOR SELECTING FILTER
CHARACTERISTICS: THE NOISE/BW TRADE-OFF
The selected accelerometer bandwidth ultimately determines
the measurement resolution (smallest detectable acceleration).
Filtering can be used to lower the noise floor to improve the
resolution of the accelerometer. Resolution is dependent on the
analog filter bandwidth at XOUT, YOUT, and ZOUT.
The output of the ADXL335 has a typical bandwidth of greater
than 500 Hz. The user must filter the signal at this point to limit
aliasing errors. The analog bandwidth must be no more than
half the analog-to-digital sampling frequency to minimize
aliasing. The analog bandwidth can be further decreased to
reduce noise and improve resolution.
The ADXL335 noise has the characteristics of white Gaussian
noise, which contributes equally at all frequencies and is
described in terms of μg/√Hz (the noise is proportional to the
square root of the accelerometer bandwidth). The user should
limit bandwidth to the lowest frequency needed by the applica-
tion to maximize the resolution and dynamic range of the
accelerometer.
With the single-pole, roll-off characteristic, the typical noise of
the ADXL335 is determined by
)
1.6
(
×
×
=
BW
Density
Noise
Noise
rms
Often, the peak value of the noise is desired. Peak-to-peak noise
can only be estimated by statistical methods. Table 6 is useful
for estimating the probabilities of exceeding various peak
values, given the rms value.
Table 6. Estimation of Peak-to-Peak Noise
Peak-to-Peak Value
% of Time that Noise Exceeds
Nominal Peak-to-Peak Value
2 × rms
32
4 × rms
4.6
6 × rms
0.27
8 × rms
0.006
USE WITH OPERATING VOLTAGES OTHER THAN 3 V
The ADXL335 is tested and specified at VS = 3 V; however, it
can be powered with VS as low as 1.8 V or as high as 3.6 V. Note
that some performance parameters change as the supply voltage
is varied.




Html Pages

1  2  3  4  5  6  7  8  9  10  11 


Datasheet Download



Powiązane numery części

Numer częściSzczegółowy opis komponentówHtml ViewProducent
ADXL330_07Small Low Power 3-Axis ±3 g i MEMS® Accelerometer 1 2 3 4 5 MoreAnalog Devices
SCA3000-D013-AXIS LOW POWER ACCELEROMETER WITH DIGITAL SPI INTERFACE 1 2 3 4 VTI technologies
SCA3000-D023-AXIS LOW POWER ACCELEROMETER WITH DIGITAL I2C INTERFACE 1 2 3 4 VTI technologies
SCA3000-E013-AXIS ULTRA LOW POWER ACCELEROMETER WITH DIGITAL SPI INTERFACE 1 2 3 4 VTI technologies
SCA3000-E023-AXIS ULTRA LOW POWER ACCELEROMETER WITH DIGITAL I2C INTERFACE 1 2 3 4 VTI technologies
SCA3000-E043-AXIS ULTRA LOW POWER ACCELEROMETER WITH DIGITAL SPI INTERFACE 1 2 3 4 VTI technologies
SCA3000-E053-AXIS ULTRA LOW POWER ACCELEROMETER WITH DIGITAL SPI INTERFACE 1 2 3 4 VTI technologies
STEVAL-MKI006V1MEMS 3-axis - ±2g/±8g digital output low power linear accelerometer evaluation board based on LIS302DL 1 2 3 4 STMicroelectronics
STEVAL-MKI004V1MEMS 3-axis - ±2g/±6g digital output low voltage linear accelerometer evaluation board based on LIS3LV02DQ 1 2 3 4 STMicroelectronics
LIS3LV02DL_08MEMS inertial sensor 3-axis - ±2g/±6g digital output low voltage linear accelerometer 1 2 3 4 5 MoreSTMicroelectronics

Link URL

Czy Alldatasheet okazała się pomocna?  [ DONATE ]  

O Alldatasheet   |   Reklama   |   Kontakt   |   Polityka prywatności   |   Dodaj do ulubionych   |   Linki   |   Lista producentów
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl