MMA2301D Datasheet, PDF (5/7 Pages) Motorola, Inc – Surface Mount Micromachined Accelerometer

Freescale Semiconductor, Inc.
BASIC CONNECTIONS
Pinout Description
N/C
1
N/C
2
N/C
3
ST
4
V_OUT
5
STATUS
6
V_SS
7
V_DD
8
16 N/C
15 N/C
14 N/C
13 N/C
12 N/C
11 N/C
10 N/C
9 N/C
Pin Descriptions
Pin No.
Pin Name
1 thru 3
N/C
4
ST
5
V_OUT
6
STATUS
7
8
9 thru 13
V_SS
V_DD
Trim pins
14 thru 16
—
Description
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_DD
Logic
Input
C1
0.1 µF
MMA2301D ⁶
4 ST
8 V_DD
V_OUT ⁵
R1
1 kΩ
7 V_SS
C2
0.01 µF
Status
Output
Signal
PCB Layout
STATUS
P1
ST
P0
V_OUT
R
A/D In
V_SS
1 kΩ C 0.01 µF
C 0.1 µF
V_DD
V_RH
C 0.1 µF
V_SS
C 0.1 µF
V_DD
Power Supply
Figure 4. Recommend PCB Layout for Interfacing
Accelerometer to Microcontroller
NOTES:
• Use a 0.1 µF capacitor on V_DD to decouple the power
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 Figure 4
• 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.
• 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. This
will prevent aliasing errors.
Figure 3. SOIC Accelerometer with Recommended
Connection Diagram
Motorola Sensor Device Data
For More Information On This Product,
Go to: www.freescale.com
MMA2301D
5