MMA2300DR2 - Motorola / Freescale Semiconductor

MOTOROLA

SEMICONDUCTOR TECHNICAL DATA Order Number: MMA2300 D

Rev. 3, 06/2004

REV 3

Surface Mount

Micromachined Accelerometer

The MMA series of silicon capacitive, micromachined accelerometers features

signal conditioning, a 4-pole low pass filter and temperature compensation. Zero-g

offset full scal e span and filter cut-of f are factory set and require no external devices.

A full system self-test capability verifies system functionality.

Features

• Integ ral Sign al Cond itioning

• Linear Output

• Ratiometric Performance

• 4th Order Bessel Filter Preserves Pulse Shape Integrity

• Calibrated Self-test

• Low Voltage Detect, Clock Monitor, and EPROM Parity Check Status

• Transducer Hermet ical ly Sealed at Wafer Level for Superior Reliabi lity

• Robust Design, High Shocks Surviv ability

Typical Applications

• Vibration Monitoring and Recording

• Impact Monitoring

ORDERING INFORMATION

Figure 1. Simplified Accelerometer Functional Block Diagram

Device Temperature

Range Package

MMA2300D – 40 to +125°C SOIC-16

MMA2300DR2 – 40 to +125°C SOIC-16, Tape & Reel

MMA2300D

16 LEAD SOIC

CASE 475-01

MMA2300D: X AXIS SENSITIVITY

MICROMACHINED

ACCELEROMETER

±250g

PIN ASSIGNMENT

N/C

VOUT

STATUS

VSS

VDD

N/C

G-Cell

Sensor Integrator Gain Filter Temp

Comp

Self-test Contr ol Logic &

EPROM

Trim Circuits Clock

Gen.

Oscillator

VDD

VOUT

VSS

Status

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MMA2300D Motorola Sensor Device Data

Maximum Ratings

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

NOTES:

1. Dropped onto concret e surface fr om any axis.

ELECTRO STATIC DISCHARGE (ESD)

WARNING: This device is sensitive to electrostatic

discharge.

Although the Motorola accelerometers contain internal 2kV

ESD prote ction circ uitry, extra prec autio n must be t ak en by the

user to prot ect the chip fr om ESD. A charg e of over 2000 volts

can accumulate on the human body or as sociated test

equipment. A charge of this magnitude can alter the

performance or cause failure of the chip. When handling the

accelerometer, proper ESD precautions should be followed to

avoid ex posing the device to discharges which may be

detrimental to its performance.

Rating Symbol Value Unit

Powered Acceleration (all axes) Gpd 1500 g

Unpowered Acceleration (all axes) Gupd 2000 g

Supply Voltage VDD –0.3 to +7.0 V

Drop Test (1) Ddrop 1.2 m

Storage Temperature Range Tstg –40 to +125 °C

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Motorola Sensor Device Data MMA2300D

Operating Characteristics

(Unless otherwise noted: –40°C ≤ TA ≤ +105°C, 4.75 ≤ VDD ≤ 5.25, Acceleration = 0g, Loaded output(1))

NOTES:

1. For a loaded output the measurements are observed after an RC filter consisting of a 1 kΩ resistor and a 0.01 µF capac itor to gr ou n d.

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

3. Within the supply range of 4.75 and 5.25 volts, the device operates as a fully calibrated linear accelerometer. Beyond these s uppl y limit s the device may

operate as a linear device bu t is not guaranteed to be in calibration.

4. The devic e can measure both + and – accelera tion. With no input accelerat ion the output is at midsupply. For posit ive accelera tion the o utput will incre ase

above VDD/2 and for negative acceleration the output will decrease below VDD/2.

5. The devic e i s calibrated at 35g.

6. At clock frequency ≅70 kHz.

7. T h e di g i tal in p ut pin has an in te r n al pull-d o w n cu r r en t s o ur c e to prevent inadvertent self test initiat ion due to external board level leakages.

8. Time for the output to reach 90% of it s final value after a self-test is initiated.

9. Time for amp lifiers to recover after an acceleration signal causing them to saturate.

10. Preserves phase margin (60°) to guarantee output amplifier stability.

11. A measure of the device's ability to reject an acceleration applied 90° fr om the true axis of sensitivity.

12. The Status pin output is not valid following power-up until at least one ris i ng edge has been applied to the s elf-test pin. The Status pin is hi gh whenever

the self-test input is high, as a means to check the connectivity of the self -test and S tatus pins in the applic ation.

13. The Status p in output l atch es hig h i f a Low Voltage De te ction or Cloc k F reque nc y f ailure o ccur s, o r t he EP ROM p arity cha nges to od d. The Stat us pi n ca n

be reset low if the self- test pin is pulsed with a high input for at least 100 µs, unless a fault condition continues to exist.

Characteristic Symbol Min Typ Max Unit

Operating Range (2)

Supply Voltage (3)

Supply Current

Operating Temperature Range

Acceleration Range

VDD

IDD

gFS

4.75

3.0

−40

—

5.00

—

281

5.25

6.0

+125

—

Output Signal

Zero g (TA = 25°C, VDD = 5.0 V)(4)

Zero g

Sensitivity (TA = 25°C, VDD = 5.0 V)(5)

Sensitivity

Bandwidth Response

Nonlinearity

VOFF

VOFF,V

f–3dB

NLOUT

2.4

0.47 VDD

7.6

1.488

360

−1.0

2.5

0.50 VDD

8.0

1.6

400

—

2.6

0.53 VDD

8.4

1.712

440

1.0

mV/g

mV/g/V

% FSO

Noise

RMS (10 Hz – 1 kHz)

Power Spectral Density

Clock Noise (without RC load on output)(6)

nRMS

nPSD

nCLK

—

110

2.0

2.8

—

mVrms

µV/(Hz1/2)

mVpk

Self-Test

Output Response

Input Low

Input High

Input Loading(7)

Response Time(8)

gST

VIL

VIH

IIN

tST

VSS

0.7 x VDD

−30

—

−100

2.0

0.3 x VDD

VDD

−260

µA

Status(12)(13)

Output Low (Iload = 100 µA)

Output High (Iload = 100 µA) VOL

VOH

—

VDD –0.8 —

—0.4

—V

Minimum Supply Voltage (LVD Trip) VLVD 2.7 3.25 4.0 V

Clock Monitor Fail Detection Frequency fmin 50 —260 kHz

Output Stage Perform ance

Electrical Saturation Recovery Time(9)

Full Scale Output Range (IOUT = 200 µA)

Capacitive Load Drive(10)

Output Impedence

tDELAY

VFSO

—

0.25

—

0.2

—

300

—

VDD–0.25

100

—

Mechanical Characteristics

Transverse Sensitivity(11)

Package Resonance VXZ,YZ

fPKG

—

——

10 5.0

—% FSO

kHz

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MMA2300D Motorola Sensor Device Data

PRINCIPLE OF OPERATION

The Motorola accelerometer is a surface-micromachined

integrated-circuit accelerometer.

The device consists of a surface micromachined capacitive

sensing cell (g-cell) and a CMOS signal conditioning ASIC

contained in a single integrated circuit package. The sensing

element is sealed hermetically at the wafer level us ing a bulk

micromachined “cap'' wafer.

The g-cell is a mechanical structure formed from

semiconductor materials (polysilicon) using semiconductor

proc esses (maski ng and etch ing). It c an be model ed as a se t of

beams a tta ched to a mov able centr al mass t hat move b etween

fixed beams. The movable beams can be deflected from their

rest position by subjecting the system to an acceleration

(Figure 2).

As the beams attached to the central mass move, the

dist ance from them to the fixed beams on one side will increase

by the same amount that the distance to the fixed beams on the

other side decreases. The change in distance is a measure of

acceleration.

The g-cell plates form two back-to-back capa citors

(Figure 2). As the central mass moves with acceleration, the

dist anc e betw e en the bea ms chan ge and each capacitor's

value will change, (C = NAε/D). Where A is the area of the

facing side of the beam, ε is the diel ectric constant, D is the

dist anc e betw e en the bea ms , and N is the numbe r of beams .

The CMOS ASIC uses switched capacitor techniques to

measur e the g-cell capac itors and extract the accel eration data

from the dif feren ce be twee n the two ca pac itors. The AS IC al so

signal conditions and filters (switched capacitor) the signal,

providing a high level output voltage that is ratiometric and

proportional to acceleration.

Figure 2. Simplified Transducer Physical Model

SPECIAL FEATURES

Filtering

The Motorola accelerometers contain an onboard 4-pole

switched capacitor filter. A Bessel implementation is used

because it provides a maximally flat delay response (linear

phase) th us preserving puls e shape integrit y . Because the fil ter

is realized using switched capa citor techniques, there is no

requirement for external passive components (resistors and

capacitors) to set the cut-off frequency.

Self-Test

The sensor provides a self-test feature that allows the

verification of the mechanical and electrical integrity of the

accelerometer at any time before or after in stallation. This

feature is critical in applications such as automotive airbag

systems where system integrity must be ensured over the life of

the vehicle. A fourth “plate'' is used in the g-cell as a self-test

plate. When the user applies a logic high input to the self-test

pin, a calibrated potential is applied across the self-test plate

and the moveable plate. The resulting el ectrostatic force

(Fe = 1/2AV2/d2) causes the center plate to deflect. The

result ant deflec tion is m easured by the a cceleromete r's control

ASIC and a prop ortiona l outp ut vol tag e resu lts . This procedure

assures that both the mechanical (g-cell) and electronic

sections of the accelerometer are functioning.

Ratiometricity

Ratiometricity simply means that the output offset voltage

and sensitivity will sc ale linearly with applied supply voltage.

That is, as you increase su pply voltage the sensitivity a nd offset

inc rease linea rly; as supply vo ltage d ecrea ses, offset and

sensitivity decrease linearly. This is a key feature when

interfacing to a microcontroller or an A/D converter because it

provides system level cancellation of supply induced erro rs in

the analog to digital conversion process.

Status

Motorola accelerometers include fault detection circuitry and

a fault latch. The Status pin is an output from the fault latch,

OR'd with self-test, and is set high whenever one (or more) of

the following events occur:

• Supply voltage falls below the Low Voltage Detect (LVD)

voltage threshold

• Clock oscillator falls below the clock monitor

minimu m frequency

• Parity of the EPROM bits becomes odd in

number.

The fault la tch can be reset by a fallin g edge on th e self-te st

input pin, unless one (or more) of the fault conditions continues

to exist.

Acceleration

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Motorola Sensor Device Data MMA2300D

BASIC CONNECTIONS

Pinout Description

Figure 3. SOIC Accelerometer with Recommended

Connection Diagram

Figure 4. Recommended PCB Layout for Interfacing

Accelerometer to Microcontroller

NOTES:

• Use a 0.1 µF capacitor on VDD to decouple the power

source.

• Physical coupling distance of the accelerometer to the

microcontroller should be minimal.

• Place a gro und p lane beneat h the accel erome ter to redu ce

noise, the ground plane should be attached to all of the open

ended terminals shown in Figure 4.

• Use an RC filter of 1 kΩ and 0.01 µF on the output of the

accelerometer to minimize clock noise (from the switc hed

capacitor filter circuit).

• PCB layout of power and ground should not couple power

supply noise.

• Accelerom eter and microcontroller should not be a high

current path.

• A/D sa mplin g rate and any externa l power suppl y switch ing

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 ST Logic input pin used to initiate

self-test.

OUT Output voltage of the

accelerometer.

6 STATUS Logic output pin to indicate

fault.

SS The power supply ground.

DD The power supply input.

9 thru 13 Trim pins Used for factory trim. Leave

unconnected.

14 thru 16 — No internal connection. Leave

unconnected.

N/C

VOUT

STATUS

VSS

VDD

N/C

MMA2300D

VOUT Output

Signal

1 kΩ

0.01 µF

Logic

Input

VDD

0.1 µF

6Status

8VDD

VSS

A/D In

VRH

VSS

VDD

VOUT

VSS

VDD

0.01 µF1 kΩ

0.1 µF

Power Supply

0.1 µF

P1STATUS

Microcontroller

Accelerometer

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MMA2300D Motorola Sensor Device Data

−x

Direction of Earth’s gravity field.*

* When positioned as shown, the Earth’s gravity will result in a positive 1g output.

87654321

9 10111213141516

16-Pin SO IC Package

N/C pins are recommended to be left FLOATING

Front View Side View

Top View

Static Acceleration Sensing Direction

Dynamic Acce leration Sensing Direction

Acceleration of the package

in the +X direction (center

plate moves in the −X

direction) will result in an

increase in the output.

Activation of Self Test

moves the center plate in

the −X direction, resulting in

an increase in the output.

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Motorola Sensor Device Data MMA2300D

PACKAGE DIMENSIONS

MINIMUM RECOMMENDED FOOTPRINT FOR SURFACE MOUNTED APPLICATIONS

Surface mount board layout is a critical portion of the total

design . The footprint for the su rfac e m oun t p ac k age s m us t be

the correct size to ensure proper solder connection interface

betwee n the b oard an d the p ac kage. With the c orrect f ootprin t,

the packages will self-align when subjected to a solder reflow

process. It is always recommended to desi gn boards with a

solder mask layer to avoid bridging and shorting between solder

pads.

Figure 5. Footprint SOIC-16 (Case 475-01)

DATE 05/17/01

CASE 475-01

ISSUE B

SEATING

PLANE

0.1

16 9

2 PLACES, 16 TIPS

D16X

A0.15 BT

0.13 BT

G/2

MILLIMETERS

DIM

MIN

10.15

7.40

3.30

0.35

0.76

0.25

0.10

0˚

10.16

0.25

MAX

10.45

7.60

3.55

0.49

1.14

1.27 BSC

0.32

0.25

7˚

10.67

0.75

RX 45˚

NOTES:

ALL DIMENSIONS ARE IN MILLIMETERS.

INTERPRET DIMENSIONS AND TOLERANCES

PER ASME Y14.5M, 1994.

DIMENSIONS "A" AND "B" DO NOT INCLUDE

MOLD FLASH OR PROTRUSIONS. MOLD FLASH

OR PROTRUSIONS SHALL NOT EXCEED 0.15

PER SIDE.

DIMENSION "D" DOES NOT INCLUDE DAMBAR

PROTRUSION. PROTRUSIONS SHALL NOT

CAUSE THE LEAD WIDTH TO EXCEED 0.75.

16 LEAD SOIC

0.380 in.

9.65 mm

0.050 in.

1.27 mm

0.024 in.

0.610 mm

0.080 in.

2.03 mm

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HOW TO REACH US:

USA/EUROPE/LOCATIONS NOT LISTED:JAPAN: Motorola Japan Ltd.; SPS, Technical Information Center

Motorola Literature Distribution 3-20-1 Minami-Azabu. Minato-ku, Tokyo 106-8573, Japan

P.O. Box 5405, Denver, Colorado 80217 81-3-3440-3569

1-800-521-6274 or 480-768-2130 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; Silicon Harbour Centre

2 Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong

852-26668334

HOME PAGE: http://motorola.com/semiconduc tors

MMA2300D

Information in this document is provided solely to enable system and software implementers to use Motorola products. There are no express or implied

copyright licenses granted hereunder to design or fabricate any integrated circuits or integrated circuits based on the information in this document.

Motorola reserves the ri ght to mak e changes withou t further no tice to any prod ucts herein. Moto rola makes no warranty, r epresenta tion o r gu arante e

regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the ap plic a tion or use o f any pr odu ct

or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be

provided in Motorola data sheets and/or speci fications can and do vary in different applications and actual performance may vary over time. All operating

parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does not convey any license

under i ts patent rights nor t he rig hts of others . Motor ola prod ucts are not desi gned , intende d, or aut horiz ed for u se as comp onents in syste ms intended fo r

surgical implant into the body , or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product

could cre ate a situation where per sonal injury or death may o ccur. Should B uyer purchase or use Moto rola products for any such un intended o r

unauthorized application, Buyer shall in demnify and h old Motorola and its officers, emplo yees, subsidiar ies, affiliates, and distr ibu tors ha rmles s ag ainst al l

claims, costs, damages, and expenses, and reasonabl e attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated

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MOTOROLA and the Stylized M Logo are registered in the US Patent and Trademark Office. All other product or service names are the property of their

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