1

Motorola Sensor Device Data

Micromachined Accelerometer

±40g

The MMAS40G family of silicon capacitive, micro–machined accelerometers

features integral signal amplification, signal conditioning, a 4–pole low–pass

filter and temperature compensation. Zero–G offset, full scale span and filter

roll–off are factory set and require no external passives. A calibrated self–test

feature mechanically displaces the seismic mass with the application of a digital

self–test signal.

The MMAS40G incorporates a single polysilicon seismic mass, suspended

between two fixed polysilicon plates (G–cell). The forces of acceleration move

the seismic mass, thereby resulting in a change in capacitance. The G–cell is

sealed at the wafer level, creating a particle–free environment. The G–cell

features built–in damping and over–range stops to protect it from mechanical

shock.

MMAS40G accelerometers are ideally suited for automotive crash detection

and recording, vibration monitoring, automotive suspension control, appliance

control systems, etc.

Features

• Minimum Full Scale Measurement ±40g

• Calibrated, True Self–Test

• Standard 16–Pin Plastic DIP package

• Senses Perpendicular to the Printed Circuit Board

• Integral Signal Conditioning and 4–Pole Filter

• Linear Output

• Robust, High Shock Survivability

SIMPLIFIED BLOCK DIAGRAM

g

G–CELL

4

SELF–TEST

+

+

8VS

+

A

LOW–PASS FILTER

6

BYPASS

TEMPERATURE

COMPENSATION

5

OUTPUT

7

GND

Order this document

by MMAS40G10D/D

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA

PIN NUMBER (DIP)

MMAS40G10D

DIP PACKAGE

CASE 648C–03

MICROMACHINED

ACCELEROMETER

±40g

1

N/C (1)

9

N/C (1)

2

N/C (1)

10

N/C (1)

3

N/C (1)

11

N/C (1)

4

Self–Test

12

N/C (1)

5

Output

13

N/C (1)

6

Bypass (2)

14

N/C (1)

7

GND

15

N/C (1)

8VS (2)

16

N/C (1)

NOTES:

1. Internal connections. All N/C should be

tied to gnd, except pin 11 which must be

tied to pin 8.

2. Bypass to ground with 0.1

µF ceramic

capacitor for specified system perfor-

mance.

1

2 3

4 5

6 7

8

9

10

11

12

13

14

15

16

REV 1