© Freescale Semiconductor, Inc., 2007. All rights reserved.
AN3376
Rev 3, 08/2007
Freescale Semiconductor
Application Note
The MMA73x0L Analog Output
Accelerometer Evaluation Boards
by: Kimberly Tuck and John Young
Systems and Applications Engineers
Tempe, AZ
INTRODUCTION
This application note describes the MMA7360L (1.5g & 6g),
MMA7340L (3g & 11g) and MMA7330L (4g & 12g) evaluation
boards for Freescale’s multi-axis (X, Y, Z) analog output
LGA-14 packaged 3x5x1 mm
3
variable capacitance sensing
accelerometers. This document provides the information
about the evaluation board featuring the accelerometer
devices. The operation of the MMA73x0L accelerometers are
explained including the circuit descriptions and diagrams,
showing the pin-outs with the corresponding functionality of
the features. This document also includes a quick start guide
using the evaluation board.
The accelerometer evaluation boards are small circuit
boards intended to be used for evaluating the accelerometers
and developing prototypes quickly without requiring a PCB to
be designed to accommodate for the small LGA package. It
also provides a means for understanding the best mounting
position and location of an accelerometer in the product with
the provided board mounting points.
Some examples of the applications for these
accelerometers are the following:
3D-Gaming: Tilt and Motion Sensing, Event Recorder
HDD MP3 Player: Freefall Detection
Laptop PC: Freefall Detection, Anti-Theft
Cell Phone: Image Stability, Text Scroll, Motion Dialing,
E-Compass
Pedometer: Motion Sensing
PDA: Text Scroll
Navigation and Dead Reckoning: E-Compass Tilt
Compensation
Robotics: Motion Sensing
DESCRIPTION
The MMA73x0L accelerometers are surface-
micromachined integrated-circuit accelerometers. These
devices consist of a capacitive sensing g-cell consisting of an
X-Y and a Z cell all within a single package, which is sealed
hermetically at the wafer level using a bulk micromachined
cap wafer. The g-cell is the sensing element of the system
which consists of polysilicon mechanical structures.
Acceleration is detected when a displacement in X, Y, or Z is
detected in the g-cells. The displacement creates a change in
capacitance. The ASIC uses a switched capacitor technique
to measure the g-cell capacitors and the acceleration data is
extracted from a difference in the capacitance. The ASIC
provides signal conditioning and filtering to convert the
capacitance into a high level output voltage which is
ratiometric and proportional to the acceleration. The g-cells
are combined with the signal conditioning ASIC in a single
integrated circuit package.
Table 1. MMA73x0L Accelerometer Characteristics
Part No. Acceleration
(g)
Sensitivity
(mV/g)
Zero g Output
(V)
V
DD
Supply
Voltage
(V)
I
DD
Current
(µA)
Rolloff Frequency
(Hz)
0g-Detect Package
MMA7360 1.5/6 800/206 1.65 3.3 400 400 X,Y
300 Z
Yes LGA
MMA7340 3/11 440/117.8 1.65 3.3 400 400 X,Y
300 Z
Yes LGA
MMA7330 4/12 308/83.6 1.4 2.8 400 400 X,Y
300 Z
No LGA
