Freescale Semiconductor
Technical Data
MMA6260Q
Rev. 2, 10/2004
±1.5g
Dual Axis
Micromachined Accelerometer
The MMA6200 series of low cost capacitive micromachined accelerometers
feature signal conditioning, a 1-pole low pass filter and temperature compen-
sation. Zero-g offset full scale span and filter cut-off are factory set and require
no external devices. A full system self-test capability verifies system function-
ality.
Features
•
•
•
•
•
•
•
•
•
•
High Sensitivity
Low Noise
Low Power
2.7 V to 3.6 V Operation
6mm x 6mm x 1.98 mm QFN
Integral Signal Conditioning with Low Pass Filter
Linear Output
Ratiometric Performance
Self-Test
Robust Design, High Shocks Survivability
MMA6260Q
MMA6261Q
MMA6262Q
MMA6263Q
MMA6260Q Series: X-Y AXIS SENSITIVITY
MICROMACHINED ACCELEROMETER
±1.5
g
Bottom View
Typical Applications
•
•
•
•
•
•
•
Tilt Monitoring
Position & Motion Sensing
Freefall Detection
Impact Monitoring
Appliance Control
Vibration Monitoring and Recording
Smart Portable Electronics
16 LEAD QFN
CASE 1477-01
ORDERING INFORMATION
Pin Assignment
Top View
Bandwidth
Response
50 Hz
50 Hz
300 Hz
300 Hz
150 Hz
150 Hz
900 Hz
900 Hz
I
DD
1.2 mA
1.2 mA
1.2 mA
1.2 mA
2.2 mA
2.2 mA
2.2 mA
2.2 mA
X
OUT
Y
OUT
Device Name
MMA6260Q
MMA6260QR2
MMA6261Q
MMA6261QR2
MMA6262Q
MMA6262QR2
MMA6263Q
MMA6263QR2
Case No.
1477-01
1477-01
1477-01
1477-01
1477-01
1477-01
1477-01
1477-01
Package
QFN-16, Tube
QFN-16,Tape & Reel
QFN-16, Tube
QFN-16,Tape & Reel
QFN-16,Tube
QFN-16,Tape & Reel
QFN-16, Tube
QFN-16,Tape & Reel
N/C
N/C
N/C
16 15 14 13
1
2
12
ST
11
10
9
5
N/C
N/C
N/C
N/C
V
DD
3
V
SS
4
6
N/C
7
N/C
8
N/C
© Freescale Semiconductor, Inc., 2004. All rights reserved.
N/C
V
DD
G-CELL
SENSOR
X-INTEGRATOR
X-GAIN
X-FILTER
X-TEMP
COMP
X
OUT
ST
SELF-TEST
CONTROL LOGIC &
EEPROM TRIM CIRCUITS
OSCILLATOR
CLOCK GEN
Y-INTEGRATOR
Y-GAIN
Y-FILTER
Y-TEMP
COMP
Y
OUT
V
SS
Figure 1. Simplified Accelerometer Functional Block Diagram
MAXIMUM RATINGS
(Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)
Rating
Maximum Acceleration (all axis)
Supply Voltage
Drop Test
1
Storage Temperature Range
Note:
1. Dropped onto concrete surface from any axis.
Symbol
g
max
V
DD
D
drop
T
stg
Value
Unit
g
V
m
°C
±
2000
-0.3 to +3.6
1.2
-40 to +125
ELECTRO STATIC DISCHARGE (ESD)
WARNING: This device is sensitive to electrostatic
discharge.
Although the Freescale Semiconductor accelerome-
ters contain internal 2000 V ESD protection circuitry, ex-
tra precaution must be taken by the user to protect the
chip from ESD. A charge of over 2000 volts can accumu-
late 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 precau-
tions should be followed to avoid exposing the device to
discharges which may be detrimental to its performance.
MMA6200 SERIES
2
Sensor Device Data
Freescale Semiconductor
Operating Characteristics
Unless otherwise noted: -20°C < T
A
< 85°C, 3.0 V < V
DD
< 3.6 V, Acceleration = 0g, Loaded output
1
Characteristic
Operating Range
2
Supply Voltage
3
Supply Current
MMA6260Q, MMA6261Q
MMA6262Q, MMA6263Q
Operating Temperature Range
Acceleration Range
Output Signal
Zero g (T
A
= 25°C, V
DD
= 3.3 V)
4
Zero g
Sensitivity (T
A
= 25°C, V
DD
= 3.3 V)
Sensitivity
Bandwidth Response
MMA6260Q
MMA6261Q
MMA6262Q
MMA6263Q
Nonlinearity
Noise
MMA6260Q RMS (0.1 Hz – 1 kHz)
MMA6261Q RMS (0.1 Hz – 1 kHz)
MMA6262Q RMS (0.1 Hz – 1 kHz)
MMA6263Q RMS (0.1 Hz – 1 kHz)
Power Spectral Density RMS (0.1 Hz – 1 kHz)
MMA6260Q, MMA6261Q
MMA6262Q, MMA6263Q
Self-Test
Output Response
Input Low
Input High
Pull-Down Resistance
5
Response Time
6
Output Stage Performance
Full-Scale Output Range (I
OUT
= 200 µA)
Capacitive Load Drive
Output Impedance
Power-Up Response Time
MMA6260Q
MMA6261Q
MMA6262Q
MMA6263Q
Mechanical Characteristics
Transverse Sensitivity
8
7
Symbol
V
DD
I
DD
I
DD
T
A
g
FS
V
OFF
V
OFF
, T
A
S
S, T
A
f
_3dB
f
_3dB
f
_3dB
f
_3dB
NL
OUT
n
RMS
n
RMS
n
RMS
n
RMS
n
PSD
n
PSD
V
ST
V
IL
V
IH
R
PO
t
ST
V
FSO
C
L
Z
O
t
RESPONSE
t
RESPONSE
t
RESPONSE
t
RESPONSE
V
ZX
,
YX
,
ZY
Min
2.7
—
—
-20
—
1.485
—
740
—
—
—
—
—
-1.0
—
—
—
—
—
—
0.9 V
DD
—
0.7 V
DD
43
—
V
SS
+0.25
—
—
—
—
—
—
-5.0
Typ
3.3
1.2
2.2
—
1.5
1.65
2.0
800
0.015
50
300
150
900
—
1.8
3.5
1.3
2.5
300
200
—
—
—
57
2.0
—
—
50
14
2.0
4.0
0.7
—
Max
3.6
1.5
3.0
+85
—
1.815
—
860
—
—
—
—
—
+1.0
—
—
—
—
—
—
V
DD
0.3 V
DD
V
DD
71
—
V
DD
-0.25
100
300
—
—
—
—
+5.0
Unit
V
mA
mA
°C
g
V
mg/°C
mV/g
%/°C
Hz
Hz
Hz
Hz
% FSO
mVrms
ug/√Hz
V
V
V
kΩ
ms
V
pF
Ω
ms
ms
ms
ms
% FSO
Notes:
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 to ground.
2. These limits define the range of operation for which the part will meet specification.
3. Within the supply range of 2.7 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. The device can measure both + and - acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above V
DD
/2. For negative acceleration, the output will decrease below V
DD
/2.
5. The digital input pin has an internal pull-down resistance to prevent inadvertent self-test initiation due to external board level leakages.
6. Time for the output to reach 90% of its final value after a self-test is initiate.
7. Preserves phase margin (60°) to guarantee output amplifier stability.
8. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.
MMA6200 SERIES
Sensor Device Data
Freescale Semiconductor
3
PRINCIPLE OF OPERATION
The Freescale Semiconductor accelerometer is a surface-
micromachined integrated-circuit accelerometer.
The device consists of a surface micromachined capacitive
sensing cell (g-cell) and a signal conditioning ASIC contained in
a single integrated circuit package. The sensing element is
sealed hermetically at the wafer level using a bulk microma-
chined
cap
wafer.
The g-cell is a mechanical structure formed from semicon-
ductor materials (polysilicon) using semiconductor processes
(masking and etching). It can be modeled as a set of beams at-
tached 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 2).
As the beams attached to the central mass move, the dis-
tance 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 plates form two back-to-back capacitors
(Figure 2). As the center plate moves with acceleration, the dis-
tance between the plates changes and each ca
p
acitor's value
SPECIAL FEATURES
Filtering
These Freescale Semiconductor accelerometers contain an
onboard single-pole switched capacitor filter. Because the filter
is realized using switched capacitor techniques, there is no re-
quirement for external passive components (resistors and ca-
pacitors) to set the cut-off frequency.
Self-Test
The sensor provides a self-test feature allowing the verifica-
tion of the mechanical and electrical integrity of the accelerom-
eter at any time before or after installation. A fourth
plate
is used
in the g-cell as a self-test plate. When a logic high input to the
self-test pin is applied, a calibrated potential is applied across
the self-test plate and the moveable plate. The resulting electro-
static force (Fe =
1
/
2
AV
2
/d
2
) causes the center plate to deflect.
The resultant deflection is measured by the accelerometer's
ASIC and a proportional output voltage results. This procedure
assures both the mechanical (g-cell) and electronic sections of
the accelerometer are functioning.
Freescale Semiconductor accelerometers include fault de-
tection circuitry and a fault latch. Parity of the EEPROM bits be-
comes odd in number.
Self-test is disabled when EEPROM parity error occurs.
will change, (C = Aε/D). Where A is the area of the plate,
ε
is the dielectric constant, and D is the distance between
the plates.
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.
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 in-
crease linearly; as supply voltage decreases, offset and sensi-
tivity decrease linearly. This is a key feature when interfacing to
a microcontroller or an A/D converter because it provides sys-
tem level cancellation of supply induced errors in the analog to
digital conversion process.
Acceleration
Figure 2. Simplified Transducer Physical Model
MMA6200 SERIES
4
Sensor Device Data
Freescale Semiconductor
BASIC CONNECTIONS
Top View
ST
X
OUT
Y
OUT
V
SS
V
DD
R
1 kΩ
R
1 kΩ
C 0.1
µF
V
RH
C 0.1
µF
C 0.1
µF
A/D IN
C 0.1
µF
A/D IN
MICROCONTROLLER
ACCELEROMETER
P0
X
OUT
Y
OUT
N/C
N/C
V
SS
C 0.1
µF
V
DD
16 15 14 13
N/C
N/C
1
2
12
ST
11
10
9
5
N/C
N/C
N/C
N/C
V
DD
3
V
SS
4
6
N/C
7
N/C
8
N/C
POWER SUPPLY
Figure 3. Pinout Description
Figure 5. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
Pin No.
1, 5 - 7, 13, 16
14
15
3
4
2, 8 - 11
12
Pin
Name
N/C
Y
OUT
X
OUT
V
DD
V
SS
N/C
ST
Description
No internal connection.
Leave unconnected.
Output voltage of the accelerometer. Y
Direction.
Output voltage of the accelerometer. X
Direction.
Power supply input.
The power supply ground.
Used for factory trim.
Leave unconnected.
Logic input pin used to initiate
self-test.
V
DD
3
0.1
µF
4
MMA6260Q
Series
V
DD
Y
OUT
14
1 kΩ
0.1
µF
V
SS
X
OUT
15
ST
1 kΩ
Notes:
1. Use 0.1 µF capacitor on V
DD
to decouple the power
source.
2. Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
3. Flag underneath package is connected to ground.
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 5.
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).
6. PCB layout of power and ground should not couple power
supply noise.
7. Accelerometer and microcontroller should not be a high
current path.
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 (16 kHz for Low I
DD
and 52 kHz for Standard
I
DD
for the sampling frequency). This will prevent aliasing
errors.
12
Logic
Input
0.1
µF
Figure 4. Accelerometer with Recommended Connection
Diagram
MMA6200 SERIES
Sensor Device Data
Freescale Semiconductor
5
京公网安备 11010802033920号
EEWORLD
