Motorola Sensor Device Data

MMA3201D

5

BASIC CONNECTIONS

Pinout Description

Figure 3. SOIC Accelerometer with Recommended

Connection Diagram

PCB Layout

Figure 4. Recommended PCB Layout for Interfacing

Accelerometer to Microcontroller

NOTES:

•

Use a 0.1

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 k

Ω 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.

Pin No.

Pin Name

Description

1 thru 3

—

Leave unconnected.

4

—

No internal connection. Leave

unconnected.

5

ST

Logic input pin used to initiate

self-test.

Output voltage of the

accelerometer. X Direction.

7

STATUS

Logic output pin to indicate

fault.

The power supply ground.

The power supply input.

10

Power supply input (Analog).

11

Output voltage of the

accelerometer. Y Direction.

12 thru 16

—

Used for factory trim. Leave

unconnected.

17 thru 19

—

No internal connection. Leave

unconnected.

20

GND

Ground.

14

15

16

17

18

19

20

8

7

6

5

4

3

2

1

13

N/C

ST

STATUS

GND

N/C

N/C

N/C

N/C

N/C

N/C

12

10

9

11

N/C

N/C

N/C

N/C

N/C

10

MMA3201D

ST

R1

1 k

Ω

C2

0.01

µF

5

9

8

Logic

Input

C1

0.1

µF

7

6

C3

0.01

µF

R2

1 k

Ω

11

Status

X Output

Signal

Y Output

Signal

P0

A/D In

ST

0.01

µF

C

1 k

Ω

0.1

µF

0.1

µF

Power Supply

C

R

C

0.1

µF

P1

STATUS

A/D In

R

0.01

µF

C

1 k

Ω

C

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com