MEMSIC MXD2020GL/ML/NL/HL

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2002.08.29.1

ABSOLUTE MAXIMUM RATINGS*

Storage Temperature ……….…………-65

°C to +150°C

Acceleration ……………………………………..50,000 g

*Stresses above those listed under Absolute Maximum Ratings may cause permanent

damage to the device. This is a stress rating only; the functional operation of the

device at these or any other conditions above those indicated in the operational

sections of this specification is not implied. Exposure to absolute maximum rating

conditions for extended periods may affect device reliability.

Pin Description: LCC-8 Package

Pin

Name

Description

1

Temperature (Analog Voltage)

2

Y-Axis Acceleration Digital Signal

3

Gnd

Ground

4

Analog Supply Voltage

5

X-Axis Acceleration Digital Signal

6

2.5V Reference

7

Sck

Optional External Clock

8

Digital Supply Voltage

Ordering Guide

Model

Package

Style

Digital

Output

Temperature

Range

MXD2020GL

LCC - 8

100 Hz

0 to 70

°C

MXD2020HL

LCC - 8

400Hz

0 to 70

°C

MXD2020ML

LCC - 8

100 Hz

-40 to 105

°

MXD2020NL

LCC - 8

400 Hz

-40 to 105

°

All parts are shipped in tape and reel packaging.

8

4

1

2

3

7

6

5

Top View

X +g

Y +g

Note: The MEMSIC logo’s arrow indicates the +X sensing

direction of the device. The +Y sensing direction is rotated 90°

away from the +X direction following the right-hand rule.

THEORY OF OPERATION

The MEMSIC device is a complete dual-axis acceleration

measurement system fabricated on a monolithic CMOS IC

process. The device operation is based on heat transfer by

natural convection and operates like other accelerometers

having a proof mass. The stationary element, or ‘proof

mass’, in the MEMSIC sensor is a gas.

A single heat source, centered in the silicon chip is

suspended across a cavity. Equally spaced

aluminum/polysilicon thermopiles (groups of

thermocouples) are located equidistantly on all four sides of

the heat source (dual axis). Under zero acceleration, a

temperature gradient is symmetrical about the heat source,

so that the temperature is the same at all four thermopiles,

causing them to output the same voltage.

Acceleration in any direction will disturb the temperature

profile, due to free convection heat transfer, causing it to be

asymmetrical. The temperature, and hence voltage output

of the four thermopiles will then be different. The

differential voltage at the thermopile outputs is directly

proportional to the acceleration. There are two identical

acceleration signal paths on the accelerometer, one to

measure acceleration in the x-axis and one to measure

acceleration in the y-axis. Please visit the MEMSIC

website at www.memsic.com for a picture/graphic

description of the free convection heat transfer principle.