Freescale MMA7340L User Manual

Freescale Semiconductor

Technical Data

±3g - 12g Three Axis Low-g

Document Number: MMA7340L

Rev 0, 1/2007

Micromachined Accelerometer

The MMA7340L is a low power, low profile capacitive micromachined
accelerometer featuring signal conditioning, a 1-pole low pass filter,
temperature compensation, self test, 0g-Detect which detects linear freefall,
and g-Select which allows for the selection between 2 sensitivities. Zero-g
offset and sensitivity are factory set and require no external devices. The
MMA7340L includes a Sleep Mode that makes it ideal for handheld battery
powered electronics.

Features

• 3mm x 5mm x 1.0mm LGA-14 Package

• Low Current Consumption: 400 µA

• Sleep Mode: 3 µA

• Low Voltage Operation: 2.2 V – 3.6 V

• Selectable Sensitivity (±3g, ±12g)

• Fast Turn On Time (0.5 ms Enable Response Time)

• Self Test for Freefall Detect Diagnosis

• 0g-Detect for Freefall Protection

• Signal Conditioning with Low Pass Filter

• Robust Design, High Shocks Survivability

• RoHS Compliant

• Environmentally Preferred Product

• Low Cost

MMA7340L

MMA7340L: XYZ AXIS

ACCELEROMETER

±3g, ±12g

Bottom View

14 LEAD

LGA

CASE 1935-01

Typical Applications

• 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

ORDERING INFORMATION

Part Number

MMA7340LT

MMA7340LR2

Temperature

Range

–20 to +85°C 1935-01 LGA-14 Tray

–20 to +85°C 1935-01 LGA-14 Tape & Reel

Package
Drawing

Package Shipping

Top V iew

N/C

N/C

X

OUT

Y

OUT

Z

OUT

V

SS

V

DD

Figure 1. Pin Connections

14

1

2

3

4

5

6

Sleep

13

12

11

10

9

8

7

Self Test

N/C

N/C

g-Select

0g-Detect

N/C

© Freescale Semiconductor, Inc., 2007. All rights reserved.

g-Select

g-Select

V

V

DD

DD

0g-Detect

0g-Detect

Sleep

Sleep

Self Test

Self Test

G-CELL

G-CELL

SENSOR

SENSOR

OSCILLATOR

OSCILLATOR

C to V

C to V

CONVERTER

CONVERTER

SELFTEST

SELFTEST

CLOCK

CLOCK

GEN

GEN

GAIN

GAIN

+

+

FILTER

FILTER

CONTROL LOGIC

CONTROL LOGIC

NVM TRIM

NVM TRIM

CIRCUITS

CIRCUITS

V

V

SS

SS

X-TEMP

X-TEMP

COMP

COMP

Y-TEMP

Y-TEMP

COMP

COMP

Z-TEMP

Z-TEMP

COMP

COMP

Figure 2. Simplified Accelerometer Functional Block Diagram

Table 1. Maximum Ratings

(Maximum ratings are the limits to which the device can be exposed without causing permanent damage.)

Rating Symbol Value Unit

X

X

OUT

OUT

Y

Y

OUT

OUT

Z

Z

OUT

OUT

Maximum Acceleration (all axis) g

Supply Voltage V

Drop Test

Storage Temperature Range T

1. Dropped onto concrete surface from any axis.

(1)

max

DD

D

drop

stg

±5000 g

–0.3 to +3.6 V

1.8 m

–40 to +125 °C

ELECTRO STATIC DISCHARGE (ESD)

WARNING: This device is sensitive to electrostatic

discharge.

Although the Freescale accelerometer contains internal
2000 V ESD protection circuitry, extra precaution must be
taken by the user to protect the chip from ESD. A charge of
over 2000 volts can accumulate on the human body or
associated test equipment. A charge of this magnitude can

MMA7340L

2 Freescale Semiconductor

alter the performance or cause failure of the chip. When
handling the accelerometer, proper ESD precautions should
be followed to avoid exposing the device to discharges which
may be detrimental to its performance.

Sensors

Table 2. Operating Characteristics

Unless otherwise noted: –20°C < TA < 85°C, 2.2 V < VDD < 3.6 V, Acceleration = 0g, Loaded output

(1)

Characteristic Symbol Min Typ Max Unit

Operating Range

Supply Voltage
Supply Current
Supply Current at Sleep Mode
Operating Temperature Range

(2)

(3)

(4)

(4)

V

DD

I

DD

I

DD

T

A

2.2
—
—

–20

3.3

400

3

—

3.6

600

10

+85

V

µA
µA

°C

Acceleration Range, X-Axis, Y-Axis, Z-Axis

g-Select: 0
g-Select: 1

g

FS

g

FS

—
—

±3

±12

—
—

g
g

Output Signal

Zero g (T

(4)

Zero g

= 25°C, VDD = 3.3 V)

A

(5)

V

OFF

V

, T

OFF

A

1.551
—

1.65
±2.0

1.749
—

V

mg/°C

Sensitivity (TA = 25°C, VDD = 3.3 V)

3g
12g

Sensitivity

S

3g

S

(4)

S,T

12g

A

413.6

103.4
—

440
110

±0.03

466.4

116.6
—

mV/g
mV/g
%/°C

Bandwidth Response

XY

Z
Output Impedance
0g-Detect

f

-3dBXY

f

-3dBZ

Z

0g

detect

—
—

O

—

-0.4

400
300

32

0

—
—
—

+0.4

Hz
Hz
kΩ

g

Self Test

Output Response

X

, Y

OUT

Z

OUT

Input Low
Input High

OUT

∆g

∆g

STXY

STZ

V

IL

V

IH

—
—

V

0.7 V

SS

DD

-0.1

+1.0

—
—

—
—

0.3 V
V

DD

DD

g
g
V
V

Noise

Power Spectral Density RMS (0.1 Hz – 1 kHz)

(4)

n

PSD

— 350 — µg/

Hz

Control Timing

Power-Up Response Time
Enable Response Time
Self Test Response Time

(6)

(7)

(8)

t

RESPONSE

t

ENABLE

t

ST

—
—
—

1.0

0.5

2.0

2.0

2.0

5.0

ms
ms
ms

Sensing Element Resonant Frequency

XY
Z

Internal Sampling Frequency

f

GCELLXY

f

GCELLZ

f

CLK

—
—
—

6.0

3.4
11

—
—
—

kHz
kHz
kHz

Output Stage Performance

Full-Scale Output Range (I

Nonlinearity, X

Cross-Axis Sensitivity

OUT

, Y

OUT

(9)

= 30 µA) V

OUT

, Z

OUT

FSO

NL

OUT

V

XY, XZ, YZ

VSS+0.25 — VDD–0.25 V

–1.0 — +1.0 %FSO

-5.0 — +5.0 %

1. For a loaded output, the measurements are observed after an RC filter consisting of an internal 32kΩ resistor and an external 3.3nF capacitor
on the analog output for each axis and a 0.1µF capacitor on Vdd - GND.

2. These limits define the range of operation for which the part will meet specification.

3. Within the supply range of 2.2 and 3.6 V, the device operates as a fully calibrated linear accelerometer. Beyond these supply limits the device
may operate as a linear device but is not guaranteed to be in calibration.

4. This value is measured with g-Select in 3g mode.

5. The device can measure both + and – acceleration. With no input acceleration the output is at midsupply. For positive acceleration the output
will increase above V

/2. For negative acceleration, the output will decrease below VDD/2.

DD

6. The response time between 10% of full scale Vdd input voltage and 90% of the final operating output voltage.

7. The response time between 10% of full scale Sleep Mode input voltage and 90% of the final operating output voltage.

8. The response time between 10% of the full scale self test input voltage and 90% of the self test output voltage.

9. A measure of the device’s ability to reject an acceleration applied 90° from the true axis of sensitivity.

MMA7340L

Sensors
Freescale Semiconductor 3