MMA7330L Datasheet, PDF (5/10 Pages) Freescale Semiconductor, Inc – ±4g - 16g Three Axis Low-g Micromachined Accelerometer

BASIC CONNECTIONS
Pin Descriptions
Top View
N/C
N/C 1
X_{OUT 2}
14
13 Self Test
12 N/C
Y_{OUT 3}
11 N/C
Z_{OUT 4}
10 g-Select
V_SS 5
9 N/C
V_DD 6
8 N/C
7
Sleep
Figure 4. Pinout Description
Table 4. Pin Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Name
N/C
X_OUT
Y_OUT
Z_OUT
V_SS
V_DD
Sleep
NC
NC
g-Select
N/C
N/C
Self Test
N/C
Description
No internal connection
Leave unconnected
X direction output voltage
Y direction output voltage
Z direction output voltage
Power Supply Ground
Power Supply Input
Logic input pin to enable product or Sleep Mode
No internal connection
Leave unconnected
No internal connection
Leave unconnected
Logic input pin to select g level
Unused for factory trim
Leave unconnected
Unused for factory trim
Leave unconnected
Input pin to initiate Self Test
Unused for factory trim
Leave unconnected
Logic
Input
Logic
VDD Input
0.1 µF
Logic
Input
10
g-Select
13
Self Test
2
XOUT
3.3 nF
MMA7330L ₃
6 _VDD
YOUT
3.3 nF
5
VSS
7
Sleep
4
ZOUT
3.3 nF
PCB Layout
Connection Diagram
POWER SUPPLY
V_DD
C
V_SS
Sleep
g-Select
Self Test
X_OUT
Y_OUT
Z_OUT
V_RH
C
P0
P1
P2
A/D_IN
C
A/D_IN
C
A/D_IN
C
V_DD
C
V_SS
Figure 6. Recommended PCB Layout for Interfacing
Accelerometer to Microcontroller
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. 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.
4. Use a 3.3nF capacitor on the outputs of the
accelerometer to minimize clock noise (from the
switched capacitor filter circuit).
5. PCB layout of power and ground should not couple
power supply noise.
6. Accelerometer and microcontroller should not be a
high current path.
7. 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.
Figure 5. Accelerometer with Recommended
Sensors
Freescale Semiconductor
MMA7330L
5