MMA6281QR2 [FREESCALE]
+-2.5g - 10g Two Axis Low-g Micromachined Accelerometer; + -2.5g - 10克两轴低g加速度计微机械
| 型号： | MMA6281QR2 |
| 厂家： | 
Freescale |
| 描述： | +-2.5g - 10g Two Axis Low-g Micromachined Accelerometer |
| 文件： | 总11页 (文件大小：283K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Document Number: MMA6281QT
Rev 0, 10/2006
Freescale Semiconductor
Technical Data
±2.5g - 10g Two Axis Low-g
Micromachined Accelerometer
MMA6281QT
The MMA6281QT low cost capacitive micromachined accelerometer features
signal conditioning, a 1-pole low pass filter, temperature compensation and g-
Select which allows for the selection among 4 sensitivities. Zero-g offset full scale
span and filter cut-off are factory set and require no external devices. Includes a
Sleep Mode that makes it ideal for handheld battery powered electronics.
Features
MMA6281QT: XZ AXIS
ACCELEROMETER
±2.5g/3.3g/6.7g/10g
•
•
•
•
•
•
•
•
•
•
•
Selectable Sensitivity (2.5g/3.3g/6.7g/10g)
Low Current Consumption: 500 µA
Sleep Mode: 3 µA
Low Voltage Operation: 2.2 V – 3.6 V
6mm x 6mm x 1.45mm QFN
Fast Turn On Time
High Sensitivity (2.5 g)
Bottom View
Integral Signal Conditioning with Low Pass Filter
Robust Design, High Shocks Survivability
Environmentally Preferred Package
Low Cost
Typical Applications
•
•
Portable Applications: Tilt Monitoring Anti-Theft
16-LEAD
QFN
CASE 1622-02
Vibration Monitoring and Recording: Appliance Balance, Seismic,
Smart Motors)
•
•
•
•
•
•
Pedometer: Motion Sensing
PDA: Text Scroll
Navigation and Dead Reckoning: E-Compass Tilt Compensation
Gaming: Tilt and Motion Sensing, Event Recorder
Robotics: Motion Sensing
Impact Monitoring (Shipping, Handling, Black Box Event Recorder)
Top View
ORDERING INFORMATION
Device
Temp. Range
– 20 to +85°C
– 20 to +85°C
Case No.
1622-02
1622-02
Package
16 15 14 13
Sleep
MMA6281QT
MMA6281QR2
QFN-16, Tray
g-Select1
1
12
Mode
QFN-16,Tape & Reel
g-Select2
VDD
2
11 N/C
10 N/C
3
4
VSS
9 N/C
5
6
7
8
Figure 1. Pin Connections
© Freescale Semiconductor, Inc., 2006. All rights reserved.
VDD
g-Select1
g-Select2
Clock
Generator
X-Temp
Comp
XOUT
Oscillator
Gain
+
Filter
G-Cell
Sensor
C to V
Converter
Sleep Mode
Control Logic
EEPROM Trim Circuits
Z-Temp
Comp
ZOUT
VSS
Figure 2. Simplified Accelerometer Functional Block Diagram
Table 1. Maximum Ratings
(Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Rating
Maximum Acceleration (all axis)
Symbol
gmax
Value
±2000
Unit
g
V
Supply Voltage
VDD
–0.3 to +3.6
1.8
Drop Test(1)
Ddrop
Tstg
m
°C
Storage Temperature Range
1. Dropped onto concrete surface from any axis.
–40 to +125
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Freescale accelerometer contains internal
2000 V ESD protection circuitry, extra precaution must be
taken by the user to protect the chip from ESD. A charge of
over 2000 volts can accumulate on the human body or
associated test equipment. A charge of this magnitude can
alter the performance or cause failure of the chip. When
handling the accelerometer, proper ESD precautions should
be followed to avoid exposing the device to discharges which
may be detrimental to its performance.
MMA6281QT
Sensors
2
Freescale Semiconductor
Table 2. Operating Characteristics
Unless otherwise noted: –20°C < TA < 85°C, 2.2 V < VDD < 3.6 V, Acceleration = 0g, Loaded output(1)
Characteristic
Symbol
Min
Typ
Max
Unit
Operating Range(2)
Supply Voltage(3)
Supply Current
Supply Current at Sleep Mode(4)
Operating Temperature Range
Acceleration Range, X-Axis, Z-Axis
g-Select1 & 2: 00
VDD
IDD
IDD
TA
2.2
—
3.3
500
3
3.6
800
10
V
µA
µA
°C
—
–20
—
+85
gFS
gFS
gFS
gFS
—
—
—
—
±2.5
±3.3
—
—
—
—
g
g
g
g
g-Select1 & 2: 10
g-Select1 & 2: 01
±6.7
g-Select1 & 2: 11
±10.0
Output Signal
Zero g (TA = 25°C, VDD = 3.3 V)(5)
Zero g(4)
VOFF
1.485
—
1.65
±2
1.815
—
V
VOFF, TA
mg/°C
Sensitivity (TA = 25°C, VDD = 3.3 V)
2.5g
S2.5g
S3.3g
S6.7g
S10g
S,TA
444
333
167
111
—
480
360
516
387
193
129
—
mV/g
mV/g
mV/g
mV/g
%/°C
3.3g
6.7g
180
10g
Sensitivity(4)
120
±0.03
Bandwidth Response
X
Z
f-3dB
f-3dB
—
—
350
150
—
—
Hz
Hz
Noise
RMS (0.1 Hz – 1 kHz)(4)
Power Spectral Density RMS (0.1 Hz – 1 kHz)(4)
nRMS
nPSD
—
—
3.0
—
—
mVrms
350
µg/
Hz
Control Timing
Power-Up Response Time(6)
Enable Response Time(7)
tRESPONSE
tENABLE
—
—
1.0
0.5
2.0
2.0
ms
ms
Sensing Element Resonant Frequency
X
fGCELL
fGCELL
fCLK
—
—
—
6.0
3.4
11
—
—
—
kHz
kHz
kHz
Z
Internal Sampling Frequency
Output Stage Performance
Full-Scale Output Range (IOUT = 30 µA)
VFSO
VSS+0.25
–1.0
—
—
VDD–0.25
+1.0
V
Nonlinearity, XOUT, ZOUT
Cross-Axis Sensitivity(8)
NLOUT
%FSO
VXZ
—
—
5.0
%
1. For a loaded output, the measurements are observed after an RC filter consisting of a 1.0 kΩ resistor and a 0.1 µF capacitor on VDD-GND.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 2.2 and 3.6 V, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits the device
may operate as a linear device but is not guaranteed to be in calibration.
4. This value is measured with g-Select in 2.5g mode.
5. The device can measure both + and – acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above VDD/2. For negative acceleration, the output will decrease below VDD/2.
6. The response time between 10% of full scale Vdd input voltage and 90% of the final operating output voltage.
7. The response time between 10% of full scale Sleep Mode input voltage and 90% of the final operating output voltage.
8. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
MMA6281QT
Sensors
Freescale Semiconductor
3
PRINCIPLE OF OPERATION
The Freescale accelerometer is a surface-micromachined
SPECIAL FEATURES
integrated-circuit accelerometer.
g-Select
The device consists of two surface micromachined
capacitive sensing cells (g-cell) and a signal conditioning
ASIC contained in a single integrated circuit package. The
sensing elements are sealed hermetically at the wafer level
using a bulk micromachined cap wafer.
The g-cell is a mechanical structure formed from
semiconductor materials (postillion) using semiconductor
processes (masking and etching). It can be modeled as a set
of beams attached to a movable central mass that move
between fixed beams. The movable beams can be deflected
from their rest position by subjecting the system to an
acceleration (Figure 3).
The g-Select feature allows for the selection among 4
sensitivities present in the device. Depending on the logic
input placed on pins 1 and 2, the device internal gain will be
changed allowing it to function with a 2.5g, 3.3g, 6.7g, or 10g
sensitivity (Table 3). This feature is ideal when a product has
applications requiring different sensitivities for optimum
performance. The sensitivity can be changed at anytime
during the operation of the product. The g-Select1 and g-
Select2 pins can be left unconnected for applications
requiring only a 2.5g sensitivity as the device has an internal
pull-down to keep it at that sensitivity (480 mV/g).
As the beams attached to the central mass move, the
distance from them to the fixed beams on one side will
increase by the same amount that the distance to the fixed
beams on the other side decreases. The change in distance
is a measure of acceleration.
The g-cell beams form two back-to-back capacitors
(Figure 3). As the center beam moves with acceleration, the
distance between the beams changes and each capacitor's
value will change, (C = Aε/D). Where A is the area of the
beam, ε is the dielectric constant, and D is the distance
between the beams.
The ASIC uses switched capacitor techniques to measure
the g-cell capacitors and extract the acceleration data from
the difference between the two capacitors. The ASIC also
signal conditions and filters (switched capacitor) the signal,
providing a high level output voltage that is ratiometric and
proportional to acceleration.
Table 3. g-Select pin Descriptions
g-Select2
g-Select1
g-Range
2.5g
Sensitivity
480 mV/g
360 mV/g
180 mV/g
120 mV/g
0
0
1
1
0
1
0
1
3.3g
6.7g
10g
Sleep Mode
The 2 axis accelerometer provides a Sleep Mode that is
ideal for battery operated products. When Sleep Mode is
active, the device outputs are turned off, providing significant
reduction of operating current. A low input signal on pin 12
(Sleep Mode) will place the device in this mode and reduce
the current to 3 µA typ. For lower power consumption, it is
recommended to set g-Select1 and g-Select2 to 2.5g mode.
By placing a high input signal on pin 12, the device will
resume to normal mode of operation.
Acceleration
Filtering
The 2 axis accelerometer contains onboard single-pole
switched capacitor filters. Because the filter is realized using
switched capacitor techniques, there is no requirement for
external passive components (resistors and capacitors) to set
the cut-off frequency.
Figure 3. Simplified Transducer Physical Model
Ratiometricity
Ratiometricity simply means the output offset voltage and
sensitivity will scale linearly with applied supply voltage. That
is, as supply voltage is increased, the sensitivity and offset
increase linearly; as supply voltage decreases, offset and
sensitivity decrease linearly. This is a key feature when
interfacing to a microcontroller or an A/D converter because
it provides system level cancellation of supply induced errors
in the analog to digital conversion process.
MMA6281QT
Sensors
4
Freescale Semiconductor
BASIC CONNECTIONS
PCB Layout
Pin Descriptions
Top View
POWER SUPPLY
16 15 14 13
VDD
VRH
VDD
VSS
C
g-Select1
1
12
Sleep Mode
C
VSS
Sleep Mode
g-Select1
C
P0
P1
P2
g-Select2
VDD
2
11 N/C
10 N/C
3
4
g-Select2
XOUT
VSS
9
N/C
R
R
A/DIN
C
C
5
6
7
8
ZOUT
A/DIN
Figure 4. Pinout Description
Table 4. Pin Descriptions
Figure 6. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
Pin No.
Pin Name
g-Select1
g-Select2
VDD
Description
Logic input pin to select g level.
Logic input pin to select g level.
Power Supply Input
1
2
NOTES:
1. Use 0.1 µF capacitor on VDD to decouple the power
3
source. Do not exceed capacitor values of 2.2 or
3.3 µF on VDD-GND.
4
VSS
Power Supply Ground
5 - 7
N/C
No internal connection.
Leave unconnected.
2. Physical coupling distance of the accelerometer to
the microcontroller should be minimal.
8 - 11
12
N/C
Unused for factory trim.
Leave unconnected.
3. The flag underneath the package is internally
connected to ground. It is not recommended for the
flag to be soldered down.
Sleep Mode Logic input pin to enable product or
Sleep Mode.
4. Place a ground plane beneath the accelerometer to
reduce noise, the ground plane should be attached to
all of the open ended terminals shown in Figure 6.
13
14
ZOUT
N/C
Z direction output voltage.
No internal connection.
Leave unconnected.
5. Use an RC filter with 1.0 kΩ and 0.1 µF on the
outputs of the accelerometer to minimize clock noise
(from the switched capacitor filter circuit).
15
16
XOUT
N/C
X direction output voltage.
No internal connection.
Leave unconnected.
6. PCB layout of power and ground should not couple
power supply noise.
Logic
Inputs
7. Accelerometer and microcontroller should not be a
high current path.
1 kΩ
1
2
13
ZOUT
g-Select1
g-Select2
8. A/D sampling rate and any external power supply
switching frequency should be selected such that
they do not interfere with the internal accelerometer
sampling frequency (11 kHz for the sampling
frequency). This will prevent aliasing errors.
0.1 µF
VDD
MMA6281QT
3
VDD
9. PCB layout should not run traces or vias under the
QFN part. This could lead to ground shorting to the
accelerometer flag.
0.1 µF
4
VSS
1 kΩ
15
XOUT
12
Sleep Mode
0.1 µF
Logic
Input
Figure 5. Accelerometer with Recommended
Connection Diagram
MMA6281QT
Sensors
Freescale Semiconductor
5
DYNAMIC ACCELERATION
Top View
Top View
Side View
16 15 14 13
12
11
1
2
-Z
+Z
+X
-X
10
9
3
4
5
6
7
8
: Arrow indicates direction of mass movement.
16-Pin QFN Package
STATIC ACCELERATION
In 2.5g mode
Direction of Earth’s gravity field.*
Top View
Side View
XOUT
ZOUT
@
@
0g = 1.
65 V
0g =
1.65 V
XOUT @ 0g = 1.65 V
Z
OUT @ +1g = 2.13 V
XOUT @ -1g = 1.17 V
XOUT @ +1g = 2.13 V
XOUT @ 0g = 1.65 V
OUT @ -1g = 1.17 V
Z
OUT @ 0g = 1.65 V
Z
OUT @ 0g = 1.65 V
Z
XOUT @ 0g = 1.65 V
OUT @ 0g = 1.65 V
Z
* When positioned as shown, the Earth’s gravity will result in a positive 1g output.
MMA6281QT
Sensors
6
Freescale Semiconductor
MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS
Surface mount board layout is a critical portion of the total
design. The footprint for the surface mount packages must be
the correct size to ensure proper solder connection interface
6.0
0.55
between the board and the package.
4.25
With the correct footprint, the packages will self-align when
subjected to a solder reflow process. It is always
recommended to design boards with a solder mask layer to
avoid bridging and shorting between solder pads.
The flag underneath the package is internally connected to
ground. It is not recommended for the flag to be soldered
down.
12
9
1.00
1
4
Flag
Pin 1 ID (non metallic)
Solder areas
Non-Solder areas
MMA6281QT
Sensors
Freescale Semiconductor
7
PACKAGE DIMENSIONS
PAGE 1 OF 3
CASE 1622-02
ISSUE B
16-LEAD QFN
MMA6281QT
Sensors
Freescale Semiconductor
8
PACKAGE DIMENSIONS
PAGE 2 OF 3
CASE 1622-02
ISSUE B
16-LEAD QFN
MMA6281QT
Sensors
Freescale Semiconductor
9
PACKAGE DIMENSIONS
PAGE 3 OF 3
CASE 1622-02
ISSUE B
16-LEAD QFN
MMA6281QT
Sensors
Freescale Semiconductor
10
RoHS-compliant and/or Pb-free versions of Freescale products have the functionality
and electrical characteristics of their non-RoHS-compliant and/or non-Pb-free
counterparts. For further information, see http://www.freescale.com or contact your
Freescale sales representative.
How to Reach Us:
Home Page:
www.freescale.com
E-mail:
support@freescale.com
For information on Freescale’s Environmental Products program, go to http://
www.freescale.com/epp.
USA/Europe or Locations Not Listed:
Freescale Semiconductor
Technical Information Center, CH370
1300 N. Alma School Road
Chandler, Arizona 85224
+1-800-521-6274 or +1-480-768-2130
support@freescale.com
Information in this document is provided solely to enable system and software
implementers to use Freescale Semiconductor products. There are no express or
implied copyright licenses granted hereunder to design or fabricate any integrated
circuits or integrated circuits based on the information in this document.
Europe, Middle East, and Africa:
Freescale Halbleiter Deutschland GmbH
Technical Information Center
Schatzbogen 7
81829 Muenchen, Germany
+44 1296 380 456 (English)
+46 8 52200080 (English)
+49 89 92103 559 (German)
+33 1 69 35 48 48 (French)
support@freescale.com
Freescale Semiconductor reserves the right to make changes without further notice to
any products herein. Freescale Semiconductor makes no warranty, representation or
guarantee regarding the suitability of its products for any particular purpose, nor does
Freescale Semiconductor assume any liability arising out of the application or use of any
product or circuit, and specifically disclaims any and all liability, including without
limitation consequential or incidental damages. “Typical” parameters that may be
provided in Freescale Semiconductor data sheets and/or specifications can and do vary
in different applications and actual performance may vary over time. All operating
parameters, including “Typicals”, must be validated for each customer application by
customer’s technical experts. Freescale Semiconductor does not convey any license
under its patent rights nor the rights of others. Freescale Semiconductor products are
not designed, intended, or authorized for use as components in systems intended for
surgical implant into the body, or other applications intended to support or sustain life,
or for any other application in which the failure of the Freescale Semiconductor product
could create a situation where personal injury or death may occur. Should Buyer
purchase or use Freescale Semiconductor products for any such unintended or
unauthorized application, Buyer shall indemnify and hold Freescale Semiconductor and
its officers, employees, subsidiaries, affiliates, and distributors harmless against all
claims, costs, damages, and expenses, and reasonable attorney fees arising out of,
directly or indirectly, any claim of personal injury or death associated with such
unintended or unauthorized use, even if such claim alleges that Freescale
Japan:
Freescale Semiconductor Japan Ltd.
Headquarters
ARCO Tower 15F
1-8-1, Shimo-Meguro, Meguro-ku,
Tokyo 153-0064
Japan
0120 191014 or +81 3 5437 9125
support.japan@freescale.com
Asia/Pacific:
Freescale Semiconductor Hong Kong Ltd.
Technical Information Center
2 Dai King Street
Tai Po Industrial Estate
Tai Po, N.T., Hong Kong
+800 2666 8080
support.asia@freescale.com
Semiconductor was negligent regarding the design or manufacture of the part.
For Literature Requests Only:
Freescale Semiconductor Literature Distribution Center
P.O. Box 5405
Freescale™ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
All other product or service names are the property of their respective owners.
Denver, Colorado 80217
© Freescale Semiconductor, Inc., 2006. All rights reserved.
1-800-441-2447 or 303-675-2140
Fax: 303-675-2150
LDCForFreescaleSemiconductor@hibbertgroup.com
MMA6281QT
Rev. 0
10/2006
相关型号：
SI9130DB
5- and 3.3-V Step-Down Synchronous ConvertersWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135LG-T1-E3
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9135_11
SMBus Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9136_11
Multi-Output Power-Supply ControllerWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130CG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130LG-T1-E3
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9130_11
Pin-Programmable Dual Controller - Portable PCsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137DB
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9137LG
Multi-Output, Sequence Selectable Power-Supply Controller for Mobile ApplicationsWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
SI9122E
500-kHz Half-Bridge DC/DC Controller with Integrated Secondary Synchronous Rectification DriversWarning: Undefined variable $rtag in /www/wwwroot/website_ic37/www.icpdf.com/pdf/pdf/index.php on line 217
-
VISHAY
©2020 ICPDF网 联系我们和版权申明