MMA7455LT Freescale Semiconductor, MMA7455LT Datasheet

Board Mount Accelerometers 3-AXIS DIGITAL 2 4 8G

MMA7455LT

Manufacturer Part Number
MMA7455LT
Description
Board Mount Accelerometers 3-AXIS DIGITAL 2 4 8G
Manufacturer
Freescale Semiconductor
Datasheet

Specifications of MMA7455LT

Sensing Axis
X, Y, Z
Acceleration
2 g, 4 g, 8 g
Supply Voltage (max)
3.6 V
Supply Voltage (min)
2.4 V
Supply Current
400 uA
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Sensitivity
64 LSB/g
Package / Case
LGA-14
Output Type
Digital
Acceleration Range
± 2g, ± 4g, ± 8g
No. Of Axes
3
Sensor Case Style
LGA
No. Of Pins
14
Supply Voltage Range
2.4V To 3.6V
Operating Temperature Range
-40°C To +85°C
Filter Terminals
SMD
Rohs Compliant
Yes
Ic Interface Type
I2C, SPI
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Freescale Semiconductor
Technical Data
© Freescale Semiconductor, Inc., 2007-2009. All rights reserved.
±2g/±4g/±8g Three Axis Low-g
Digital Output Accelerometer
capacitive micromachined accelerometer featuring signal conditioning, a low
pass filter, temperature compensation, self-test, configurable to detect 0g
through interrupt pins (INT1 or INT2), and pulse detect for quick motion
detection. 0g offset and sensitivity are factory set and require no external
devices. The 0g offset can be customer calibrated using assigned 0g registers
and g-Select which allows for command selection for 3 acceleration ranges
(2g/4g/8g). The MMA7455L includes a Standby Mode that makes it ideal for
handheld battery powered electronics.
Features
Typical Applications
This document contains certain information on a new product.
Specifications and information herein are subject to change without notice.
MMA7455LR1
MMA7455LR2
Part Number
MMA7455LT
The MMA7455L is a Digital Output (I
Digital Output (I
3mm x 5mm x 1mm LGA-14 Package
Self-Test for Z-Axis
Low Voltage Operation: 2.4 V – 3.6 V
User Assigned Registers for Offset Calibration
Programmable Threshold Interrupt Output
Level Detection for Motion Recognition (Shock, Vibration, Freefall)
Pulse Detection for Single or Double Pulse Recognition
Sensitivity (64 LSB/g @ 2g and @ 8g in 10-Bit Mode)
Selectable Sensitivity (±2g, ±4g, ±8g) for 8-bit Mode
Robust Design, High Shocks Survivability (5,000g)
RoHS Compliant
Environmentally Preferred Product
Low Cost
Cell Phone/PMP/PDA: Image Stability, Text Scroll, Motion Dialing,
Tap to Mute
HDD: Freefall Detection
Laptop PC: Freefall Detection, Anti-Theft
Pedometer
Motion Sensing, Event Recorder
Temperature Range
2
C/SPI)
–40 to +85°C
–40 to +85°C
–40 to +85°C
ORDERING INFORMATION
2
C/SPI), low power, low profile
Package
LGA-14
LGA-14
LGA-14
13” Tape & Reel
7” Tape & Reel
Shipping
Tray
DVDD_IO
IADDR0
AVDD
GND
GND
N/C
Document Number: MMA7455L
Figure 1. Pin Connections
MMA7455L: XYZ-AXIS
MMA7455L
ACCELEROMETER
CASE 1977-01
Bottom View
±2g/±4g/±8g
14 LEAD
Top View
LGA
Rev 10, 12/2009
INT1/DRDY
SDA/SDI/SDO
SDO
N/C
N/C
INT2

MMA7455LT Summary of contents

Page 1

... Pedometer • Motion Sensing, Event Recorder ORDERING INFORMATION Part Number Temperature Range MMA7455LT –40 to +85°C MMA7455LR1 –40 to +85°C MMA7455LR2 –40 to +85°C This document contains certain information on a new product. Specifications and information herein are subject to change without notice. ...

Page 2

... Clearing the Interrupt Pins: Register $17 .....................................................................................................................15 Detecting Interrupts ......................................................................................................................................................16 DIGITAL INTERFACE ................................................................................................................................................................ Slave Interface .......................................................................................................................................................16 SPI Slave Interface ......................................................................................................................................................18 BASIC CONNECTIONS .............................................................................................................................................................19 Pin Descriptions ...........................................................................................................................................................19 Recommended PCB Layout for Interfacing Accelerometer to Microcontroller .............................................................19 REGISTER DEFINITIONS .........................................................................................................................................................21 SOLDERING AND MOUNTING GUIDELINES FOR THE LGA ACCELEROMETER SENSOR BOARD ...................29 Sensors Freescale Semiconductor MMA7455L 2 ...

Page 3

... Correct PCB Top Metal Pattern Under Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Recommended PCB Land Pad, Solder Mask, and Signal Trace Near Package Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Stencil Design Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Temperature Coefficient of Offset (TCO) and Temperature Coefficient of Sensitivity (TCS) Distribution Charts . . . . . . . . . . . 32 MMA7455L Current Distribution Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Sensors Freescale Semiconductor MMA7455L 3 ...

Page 4

... Configuring the Interrupt settings using Register $18 with INTREG[1:0] bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 $1B: Pulse Detection Threshold Limit Value (Read/Write $1C: Pulse Duration Value (Read/Write $1D: Latency Time Value (Read/Write $1E: Time Window for 2nd Pulse Value (Read/Write $1A: Level Detection Threshold Limit Value (Read/Write Acceleration vs. Output (8-bit data Sensors Freescale Semiconductor MMA7455L 4 ...

Page 5

... If the user wants to use it, factory programming is required. If activated (pin4 on the device is active). <$1D= 0001 1101> bit pin 4 DD <$1C=0001 1100> bit 0 is GND on pin 4. If the pin is programmed it cannot be left NC. Figure 2. Simplified Accelerometer Functional Block Diagram Sensors Freescale Semiconductor Description C Enable (1) Pin Status Input Input Input Input ...

Page 6

... 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 exposing the device to discharges which may be detrimental to its performance. MMA7455L 6 Symbol Value g 5000 max AV -0 -0.3 to +3.6 DD_IO D 1.8 drop T -40 to +125 stg Unit °C Sensors Freescale Semiconductor ...

Page 7

... Turn On Response Time (Standby to Normal Mode) Turn Off Response Time (Normal to Standby Mode) Self-Test Response Time Sensing Element Resonant Frequency XY Z Nonlinearity (2 g range) Cross Axis Sensitivity recommended to tie the analog and digital supply voltages together. Sensors Freescale Semiconductor < 3.6 V, Acceleration = 0g, Loaded output. DD Symbol DD_IO ...

Page 8

... Figure 3. Simplified Transducer Physical Model Min Typ Max 0 — FS 0.5 — 127 — 0.5 — 0 — FS — 127 — 1 — 150 1 — 250 — 600 — — 1 — /D). Where A is the area of the beam, Freescale Semiconductor Unit Counts ε is the di- Sensors ...

Page 9

... By default all three axes are enabled. X and/or Y and/or Z can be disabled. There is a choice between detecting an absolute signal or a positive or negative only signal on the enabled axes. There is also a choice between doing a detection for motion where > Threshold vs. doing a detection for freefall where X & Y & Z < Threshold. Sensors Freescale Semiconductor ...

Page 10

... The detection status is monitored by the Detection LDTH[4] LDTH[3] LDTH[ Reg $18 INTREG[0] INTPIN Function 0 0 Default ) D1 D0 Reg $19 PDPL LDPL Function 0 0 Default D1 D0 Reg $18 INTREG[0] INTPIN Function 0 0 Default D1 D0 Reg $1A LDTH[1] LDTH[0] Function 0 0 Default Sensors Freescale Semiconductor ...

Page 11

... Reg $18 THOPT=1; Reg 19 LDPL=1, Set Threshold to 0.5g, which is 7 counts (16 counts/g). Set register $1A LDTH = $07 CASE 4: Freefall Detection Absolute: ||X|| <Threshold AND ||Y|| < Threshold AND ||Z||< Threshold Reg $18 THOPT=0; Reg 19 LDPL=1, Set Threshold to +/-0.5g, which is 7 counts (16 counts/g). Set register $1A LDTH = $07. Sensors Freescale Semiconductor $07 ...

Page 12

... D3 D2 PDTH[4] PDTH[3] PDTH[ PD[4] PD[3] PD[ Page 15, under the Assigning, Clear Reg $18 INTREG[0] INTPIN Function 0 0 Default D1 D0 Reg $19 PDPL LDPL Function 0 0 Default D1 D0 Reg $1B PDTH[1] PDTH[0] Function 0 0 Default D1 D0 Reg $1C PD[1] PD[0] Function 0 1 Default Sensors Freescale Semiconductor ...

Page 13

... Pulse Detection Threshold Limit Value (Read/Write PDTH[7] PDTH[6] PDTH[ $1D: Latency Time Value (Read/Write LT[7] LT[6] LT[ Sensors Freescale Semiconductor Pulse Detection Time duration Time *Note there 1.6ms delay on the interrupt signal Time nd pulse $ indicating single pulse Figure 4. Single Pulse Detection PDTH[4] PDTH[3] PDTH[ ...

Page 14

... Figure 6. Double Pulse Detection D1 D0 Reg $1B PDTH[1] PDTH[0] Function 0 0 Default D1 D0 Reg $1C PD[1] PD[0] Function 0 1 Default D1 D0 Reg $1D LT[1] LT[0] Function 0 1 Default D1 D0 Reg $1E TW[1] TW[0] Function 0 0 Default Page 15. The detection status is Time Time Time Sensors Freescale Semiconductor ...

Page 15

... After interrupt has triggered due to a detection, the interrupt pin (INT1 or INT2) need to be cleared by writing a logic 1. Then the interrupt pin should be enabled to trigger the next detection by setting logic 0. This example is to show how to reset the interrupt flags void ClearIntLatch(void) { IIC_ByteWrite(INTRST, 0x03); IIC_ByteWrite(INTRST, 0x00); } Sensors Freescale Semiconductor YDA XDA INTREG[ “ ...

Page 16

... Register ($18) and is detected 0: Interrupt assigned by INTRG[1:0] bits in Control 1 Register ($18) and is not detected set the I CDIS bit Device Address register using SPI. Figure 7 shows the timing diagram for the accelerometer 8-bit Reg $0A INT2 INT1 Function 0 0 Default 2 C communication is selected Sensors Freescale Semiconductor ...

Page 17

... The MMA7455L automatically increments the received register address commands after a write command is received. Therefore, after following the steps of a single byte write, multiple bytes of data can be written to sequential registers after each MMA7455L acknowledgment (ACK) is received. See Figure 10. Multiple Byte Writes - The Master (MCU) is writing to multiple sequential registers of the MMA7455L Sensors Freescale Semiconductor Figure 10. MMA7455L 17 ...

Page 18

... Figure 11. SPI Timing Diagram for 8-Bit Register Read (4 Wire Mode) Figure 12. SPI Timing Diagram for 8-Bit Register Read (3 Wire Mode) Figure 13. SPI Timing Diagram for 8-Bit Register Write (3 Wire Mode) MMA7455L 18 Figure 11 and Figure 13 for the timing diagram for an 8-bit data write. Freescale Semiconductor Figure 16 for Figure 12 for the Sensors ...

Page 19

... BASIC CONNECTIONS Pin Descriptions Top View DVDD_IO GND N/C IADDR0 GND AVDD Figure 14. Pinout Description Recommended PCB Layout for Interfacing Accelerometer to Microcontroller Sensors Freescale Semiconductor Table 8. Pin Descriptions Pin # Pin Name 1 DVDD_IO 2 GND 3 N/C 4 IADDR0 SDA/SDI/SDO 5 GND SDO 6 AVDD N INT1/DRDY N/C ...

Page 20

... Any external power supply switching frequency should be selected such that they do not interfere with the internal accelerometer sampling frequency (sampling frequency). This will prevent aliasing errors. 6. Physical distance of the two GND pins (Pin 2 and Pin 5) tied together should be at the shortest distance. MMA7455L 20 Figure 16. SPI Connection to MCU to and DV to decouple the power source Sensors Freescale Semiconductor ...

Page 21

... Output Value X LSB (Read only XOUT [7] XOUT [6] XOUT [ Signed byte data (2’s complement 10’h000 Reading low byte XOUTL latches high byte XOUTH to allow 10-bit reads. XOUTH should be read directly following XOUTL read. Sensors Freescale Semiconductor Bit 7 Bit 6 Bit 5 XOUT[7] XOUT[6] XOUT[ YOUT[7] YOUT[6] YOUT[5] -- ...

Page 22

... Function 0 0 Default D1 D0 Bit YOUT [9] YOUT[8] Function 0 0 Default D1 D0 Bit ZOUT [1] ZOUT[0] Function 0 0 Default D1 D0 Bit ZOUT [9] ZOUT[8] Function 0 0 Default D1 D0 Bit XOUT [1] XOUT [0] Function 0 0 Default D1 D0 Bit YOUT [1] YOUT [0] Function 0 0 Default Sensors Freescale Semiconductor ...

Page 23

... I2CDIS and SPI are available disabled. 2 DVAD[6:0 device address $0E: User Information (Read Only: Optional UI[7] UI[6] UI[5] 0/OTP 0/OTP 0/OTP UI2[7:0]: User information Sensors Freescale Semiconductor ZOUT [4] ZOUT [3] ZOUT [ PERR PERR 1: Parity error is detected in trim data. Then, self-test is dis- abled 0: Parity error is not detected in trim data ...

Page 24

... XOFF[2] XOFF[1] XOFF[0] 2 LSB 1 LSB 0.5 LSB D1 D0 Bit XOFF [9] XOFF [8] Function 0 0 Default D1 D0 Bit YOFF [1] YOFF [0] Function 0 0 Default YOFF[2] YOFF[1] YOFF[0] 2 LSB 1 LSB 0.5 LSB D1 D0 Bit YOFF [9] YOFF [8] Function 0 0 Default YOFF[8] 128 LSB Sensors Freescale Semiconductor ...

Page 25

... GLVL [1:0] 00 selected for measurement range. 10 selected for measurement range. 01 selected for measurement range. STON 0: Self-test is not enabled 1: Self-test is enabled MODE [1:0] 00: Standby Mode Table 11. Configuring the Mode using Register $16 with MODE[1:0] bits Sensors Freescale Semiconductor ZOFF[4] ZOFF[3] ZOFF[ ZOFF[5] ZOFF[4] ...

Page 26

... D1 D0 Bit CLR_INT2 CLR_INT1 Function 0 0 Default D1 D0 Bit INTREG[0] INTPIN Function 0 0 Default “INT2” Register Bit Pulse Detection Level Detection Single or Double Pulse Detection nd Time Window = there is a latency D1 D0 Bit PDPL LDPL Function 0 0 Default Sensors Freescale Semiconductor ...

Page 27

... Min: LT[7:0] = 8’h01 = 1 ms Max: LT[7:0] = 8’hFF = 255 ms 1 LSB = 1 ms $1E: Time Window for 2nd Pulse Value (Read/Write TW[7] TW[6] TW[ Min: TW[7:0] = 8’h01 = 1 ms (Single pulse detection) Max: TW[7:0] = 8’hFF = 255 ms 1 LSB = 1 ms Sensors Freescale Semiconductor LDTH[4] LDTH[3] LDTH[ PDTH[4] PDTH[3] PDTH[2] 0 ...

Page 28

... OUT @ 0g = $00 FS Mode Acceleration -2g -1g 0g +1g +2g -4g -1g 0g +1g +4g -8g -1g 0g +1g +8g Direction of Earth's gravity field.* Side View Top Bottom $00 OUT $00 OUT Z @ +1g = $3F OUT Bottom Top $00 OUT $00 OUT Z @ -1g = $C1 OUT Output $80 $C1 $00 $3F $7F $80 $E1 $00 $1F $7F $80 $F1 $00 $0F $7F Freescale Semiconductor Sensors ...

Page 29

... Array (LGA) package platform. This section describes suggested methods of soldering these devices to the PC board for con- sumer applications. Figure 18 shows the recommended PCB land pattern for the package. Figure 18. Recommended PCB Land Pattern for the LGA Package Sensors Freescale Semiconductor MMA7455L 29 ...

Page 30

... Figure 20. Correct PCB Top Metal Pattern Under Package PCB land pattern - NSMD Wider trace SM opening = PCB land pad + 0.1mm = 1.0 x 0.7mm sq. Figure 21. Figure 21. Figure 21. Signal trace near package: 0.1mm width and min. 0.5mm length are recommended. Wider trace can be continued after these. Sensors Freescale Semiconductor ...

Page 31

... These terminations are compatible with tin-lead (Sn-Pb) as well as tin-silver-copper (Sn-Ag-Cu) solder paste soldering processes. Reflow profiles applicable to those processes can be used successfully for solder- ing the devices. Sensors Freescale Semiconductor 10x0.8mm 14x0.575mm Figure 22. Stencil Design Guidelines Figure 21 ...

Page 32

... Figure 24. MMA7455L Current Distribution Charts MMA7455L 32 Xsens_%/DegreeC_-40to85 LSL Targ et USL - -0.02 -0.01 Ysens_%/DegreeC_-40to85 LSL T arg et USL - -0.02 -0.01 Zsens_%/DegreeC_-40to85 LSL Targ et USL -0.03 -0.02 -0. Target USL 0 0.01 0.02 Target USL 0 0.01 0.02 Target USL 0 0.01 0.02 0.03 Freescale Semiconductor Sensors ...

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... Sensors Freescale Semiconductor PACKAGE DIMENSIONS CASE 1977-01 ISSUE A 14-LEAD LGA MMA7455L 33 ...

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... MMA7455L 34 PACKAGE DIMENSIONS CASE 1977-01 ISSUE A 14-LEAD LGA Sensors Freescale Semiconductor ...

Page 35

... Freescale Semiconductor product could create a situation where personal injury or death may occur. Should Buyer ...

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