MMA2301 FREESCALE [Freescale Semiconductor, Inc], MMA2301 Datasheet - Page 5

• Manufacturer Part Number: MMA2301
• Description: Surface Mount Micromachined Accelerometer
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Sensors
Freescale Semiconductor
PINOUT DESCRIPTION
Table 3. Pin Descriptions
V
14 thru 16
DD
9 thru 13
Pin No.
1 thru 3
Figure 4. SOIC Accelerometer with Recommended
0.1 µF
C1
4
5
6
7
8
Logic
Input
STATUS
V
V
N/C
N/C
N/C
OUT
V
ST
DD
SS
Pin Name
Trim pins
STATUS
4
8
7
V
V
N/C
V
ST
OUT
—
DD
SS
Connection Diagram
ST
V
V
DD
SS
1
2
3
4
5
6
7
8
MMA2301D
Leave unconnected.
Logic input pin used to initiate self-
test.
Output voltage of the accelerometer.
Logic output pin to indicate fault.
The power supply ground.
The power supply input.
Used for factory trim. Leave
unconnected.
No internal connection. Leave
unconnected.
V
OUT
16
15
13
12
10
14
11
6
5
9
0.01 µF
Description
C2
1 kΩ
R1
N/C
N/C
N/C
N/C
N/C
N/C
N/C
N/C
Status
BASIC CONNECTIONS
Signal
Output
NOTES:
•
•
•
•
•
•
switching frequency should be selected such that they do not
interfere with the internal accelerometer sampling frequency.
This will prevent aliasing errors.
PCB Layout
A/D sampling rate and any external power supply
STATUS
Use a 0.1 µF capacitor on V
source.
Physical coupling distance of the accelerometer to the
microcontroller should be minimal.
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
Use an RC filter of 1 kΩ and 0.01 µF on the output of the
accelerometer to minimize clock noise (from the switched
capacitor filter circuit).
PCB layout of power and ground should not couple power
supply noise.
Accelerometer and microcontroller should not be a high
current path.
Figure 5. Recommend PCB Layout for Interfacing
V
V
OUT
V
ST
DD
SS
C
Accelerometer to Microcontroller
Power Supply
0.1 µF
1 kΩ
R
C
C
0.01 µF
0.1 µF
DD
P1
P0
A/D In
V
RH
to decouple the power
Figure 5
V
V
DD
SS
MMA2301D
C
0.1 µF
5